Allied Warships

HNMS O 21 (P 21)

Submarine of the O 21 class

NavyThe Royal Dutch Navy
TypeSubmarine
ClassO 21 
PennantP 21 
Built byKoninklijke Maatschappij De Schelde (Vlissingen (Flushing), The Netherlands) 
Ordered19 Jun 1937 
Laid down20 Nov 1937 
Launched21 Oct 1939 
Commissioned10 May 1940 
End service2 Nov 1957 
History

Decommissioned on 2 November 1957.
Sold to be broken up for scrap on 24 January 1958. 

Former nameK XXI

Commands listed for HNMS O 21 (P 21)

Please note that we're still working on this section.

CommanderFromTo
1luitenant ter zee 1e klasse (Lt.Cdr.) Johannes Frans van Dulm, RNN10 May 194028 Mar 1944
2luitenant ter zee 2e klasse (Lt.) Frans Jan Kroesen, RNN28 Mar 194418 Oct 1945

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Noteable events involving O 21 include:


The history of HrMs O 21 as compiled on this page is extracted from O 21's patrol reports and logbooks. This information was obtained during research at the British National Archives at London and the Dutch National Archives at The Hague. Corrections and details regarding information from the enemy's side (for instance the composition of convoys attacked) is kindly provided by Mr. Platon Alexiades, a naval researcher from Canada.

10 May 1940
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from her builders yard to escape to England. She proceeds together with sister ship HrMs O 22 (Lt.Cdr. A.M. Valkenburg, RNN) to the Downs. The submarines are escorted by auxiliary patrol vessel HrMs BV 37 (former tug Schelde) (Lt. A.J. Meijer, RNN(R)).

11 May 1940
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN), HrMs O 22 (Lt.Cdr. A.M. Valkenburg, RNN) and their escort HrMs BV 37 (former tug Schelde) (Lt. A.J. Meijer, RNN(R)) arrive in the Downs where they anchor to await further orders.

12 May 1940
Several Dutch ships that escaped from the Netherlands to the Downs proceed to Portsmouth. The ships involved are;
Unfinished light cruiser HrMs Jacob van Heemskerck (Lt.Cdr. A. van Foreest, RNN),
Minesweeper HrMs Jan van Gelder (Lt. P.L.M. van Geen, RNN),
Submarine HrMs O 13 (Lt.Cdr. E.H. Vorster, RNN)
unfinished submarines HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) and HrMs O 22 (Lt.Cdr. A.M. Valkenburg, RNN).

All ships arrived safely in Portsmouth later the same day.

8 Jun 1940
After completing the outfitting of both brand new submarines, HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) and HrMs O 22 (Lt.Cdr. J.W. Ort, RNN) both depart from Portsmouth for Portland.

They arrive at Portland later the same day. At Portland both submarine conduct trials and exercises.

17 Jun 1940
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) and HrMs O 22 (Lt.Cdr. J.W. Ort, RNN) both depart from Portland for Dundee.

They are escorted by Dutch torpedo boat HrMs Z 5 (Lt.Cdr. W. van Lier, RNN)

22 Jun 1940
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) and HrMs O 22 (Lt.Cdr. J.W. Ort, RNN) and their escort HrMs Z 5 (Lt.Cdr. W. van Lier, RNN) arrive Dundee.

29 Jun 1940
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) and HrMs O 22 (Lt.Cdr. J.W. Ort, RNN) both depart from Dundee for Rosyth. They arrive at Rosyth later on the same day.

1 Jul 1940
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) and HrMs O 22 (Lt.Cdr. J.W. Ort, RNN) both depart from Rosyth to return to Dundee where they arrive later on the same day.

6 Jul 1940
After a few days of exercises out of Dundee HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Dundee for Rosyth again. She arrived at Rosyth later on the same day.

At Rosyth the submarine will undergo some modifications.

29 Jul 1940
After being modified at the Rosyth Naval Dockyard HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) and HrMs O 22 (Lt.Cdr. J.W. Ort, RNN) both conduct exercises off Rosyth.

30 Jul 1940
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) and HrMs O 22 (Lt.Cdr. J.W. Ort, RNN) both depart from Rosyth for their 1st war patrols.

They are to patrol in the North Sea.

For the daily and attack positions of HrMs O 21 during this patrol see the map below.


HrMs O 21 1st war patrolclick here for bigger map

1 Aug 1940
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) fires two torpedoes at German U-boat U-60 in the North Sea in position 55°34'N, 02°18'E. Both torpedoed missed the target.

1602 hours - Sighted conning tower of small German U-boat bearing 190°. Distance 3 to 4 nautical miles. Started attack.

1615 hours - Fired two torpedoes from 1600-1700 yards. Both torpedoes missed their target. The attack was not observed on board U-60.

9 Aug 1940
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) and HrMs O 22 (Lt.Cdr. J.W. Ort, RNN) both end their 1st war patrols at Dundee.

24 Aug 1940
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) conducts exercises off Dundee.

28 Aug 1940
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Dundee for her 2nd war patrol. She was ordered to patrol off the Norwegian Coast near Bergen.

For the daily positions of HrMs O 21 during this patrol see the map below.


HrMs O 21 2nd war patrolclick here for bigger map

12 Sep 1940
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) ended her 2nd war patrol at Dundee.

22 Sep 1940
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Dundee for her 3rd war patrol. She was ordered to patrol off the South-West coast of Norway.

For the daily positions of HrMs O 21 during this patrol see the map below.


HrMs O 21 3rd war patrolclick here for bigger map

6 Oct 1940
At 0930 hours HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) sights a German U-boat but is unable to reach a favourable attack position. By 0952 hours the enemy was no longer in sight and might have dived. Approximate position was 60°10'N, 04°48'E.

German U-boat must have been U-61. She arrived at Bergen at 1650 hours (German time).

8 Oct 1940
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) ended her 3rd war patrol at Dundee.

20 Oct 1940
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) is docked at Dundee.

27 Oct 1940
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) left dock.

25 Nov 1940
During 25 and 26 November HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) conducts exercises off Dundee.

28 Nov 1940
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Dundee for her 4th war patrol. She was ordered to patrol off the South-West coast of Norway near Stavanger.

For the daily positions of HrMs O 21 during this patrol see the map below.


HrMs O 21 4th war patrolclick here for bigger map

12 Dec 1940
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) ended her 4th war patrol at Dundee.

29 Dec 1940
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Dundee for her 5th war patrol. She was ordered to patrol off the coast of South-West Norway near Bergen.

For the daily positions of HrMs O 21 during this patrol see the map below.


HrMs O 21 5th war patrolclick here for bigger map

12 Jan 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) ended her 5th war patrol at Dundee.

27 Jan 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Dundee for her 6th war patrol. She was ordered to patrol off the coast of South-West Norway near Bergen.

For the daily positions of HrMs O 21 during this patrol see the map below.


HrMs O 21 6th war patrolclick here for bigger map

10 Feb 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) ended her 6th war patrol at Dundee.

23 Feb 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) and HrMs O 23 (Lt.Cdr. G.B.M. van Erkel, RNN) both depart from Dundee bound for Gibraltar (7th war patrol for O 21). The submarines are escorted by the British armed yacht HMS White Bear (Cdr. (retired) C.C. Flemming, RN). On 25 February the Free French minesweeper FFL La Moqueuse took over the escort through the Irish Sea.

For the daily positions of HrMs O 21 during this patrol see the map below.


HrMs O 21 7th war patrolclick here for bigger map

26 Feb 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) and HrMs O 23 (Lt.Cdr. G.B.M. van Erkel, RNN) both make a short call at Holyhead. They depart from again after a few hours for their passage to Gibraltar.

27 Feb 1941
Late in the afternoon, off Milford Haven near position 51°37'N, 05°28'W HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) and HrMs O 23 (Lt.Cdr. G.B.M. van Erkel, RNN) and their escort the Free French minesweeper FFL La Moqueuse encounter the British merchant Losada (6520 GRT, built 1921). As La Moqueuse was more than a mile behind both submarines the crew of the Losada think they were German U-boats and opened fire. To prevent being hit both submarines crash dive. The crew of La Moqueuse had not seen both submarines dive and was now also under the impression that a German U-boat was nearby and dropped three depth charges. O 21 was the target of the attack but sustains no damage. Both submarines surfaced shortly afterwards.

4 Mar 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm) does not sight her escort at the rendez vouz. The British corvette HMS La Malouine (Lt.Cdr. (retired) R.W. Keymer, RN) was supposed to meet her and escort her to convoy OG 54. O 21 now proceeded along the expected path of the convoy independently.

7 Mar 1941
Near position 44°54'N, 22°45'W HrMs O 21 (Lt.Cdr. J.F. van Dulm) finally sights and joins convoy OG 54.

13 Mar 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) leaves convoy OG 54 and proceeded to Gibraltar.

14 Mar 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Gibraltar.

27 Mar 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) carries out exercises off Gibraltar with HMS Alouette (Lt. R.F.R. Yarde-Buller, RNVR), HMS Erin (A/Cdr. J.O. Davies, RNR), HMS Lord Hotham (Skr. J.W. Morris, RNR) and HMS Leyland (Skr. H. Crighton, RNR).

28 Mar 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) carries out exercises off Gibraltar with HMS Fortune (Lt.Cdr. E.N. Sinclair, RN), HMS Kingston Chrysolite (Skr. G.T. Lilley, DSC, RNR) and HMS Haarlem (T/Lt. L.B. Merrick, RNR).

3 Apr 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) carries out an A/S exercise off Gibraltar with HMS Fleur de Lys (Lt.Cdr. L.M. Carter, RNR), and HMS Coreopsis (Lt.Cdr. A.H. Davies, RNVR).

Upon completion of this exercise all three ships joined the escort of convoy HG 58 (8th war patrol).

For the daily positions of HrMs O 21 during this patrol see the map below.


HrMs O 21 8th war patrolclick here for bigger map

12 Apr 1941
In position 43°05'N, 21°56'W HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) leaves convoy HG 58 to join convoy OG 58.

13 Apr 1941
Near position 47°27'N, 23°16'W HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) joins the escort of convoy OG 58.

21 Apr 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Gibraltar with convoy OG 58.

1 May 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) carries out exercises off Gibraltar with HMS Faulknor (Capt. A.F. de Salis, RN) and HMS Azalea (Lt. G.C. Geddes, RNR). Later exercises are carried out with aircraft from HMS Ark Royal (Capt. L.E.H. Maund, RN).

6 May 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Gibraltar and joins the escort of convoy HG 61 (9th war patrol).
HrMs O 21 9th war patrolclick here for bigger map

13 May 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from convoy HG 61 and joins the escort of convoy OG 61.

19 May 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Gibraltar with convoy OG 61.

25 May 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) is docked at Gibraltar.

1 Jun 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) left dock.

4 Jun 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Gibraltar and joins the escort of convoy HG 64 (10th war patrol).

For the daily positions of HrMs O 21 during this patrol see the map below.


HrMs O 21 10th war patrolclick here for bigger map

11 Jun 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN), HMS Fleur de Lys (Lt.Cdr. L.M. Carter, RNR) and HMS Coreopsis (Lt.Cdr. A.H. Davies, RNVR) depart from convoy HG 64 to join convoy OG 64.

12 Jun 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN), HMS Fleur de Lys (Lt.Cdr. L.M. Carter, RNR) and HMS Coreopsis (Lt.Cdr. A.H. Davies, RNVR) join convoy OG 64.

18 Jun 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Gibraltar with convoy OG 64.

24 Jun 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) carries out an A/S exercise off Gibraltar with HMS Folkestone (Lt.Cdr. C.F.H. Churchill, RN) and HMS Stella Carina (Lt. J.V. Lobb, RANVR).

Upon completion of this exercise all three ships joined the escort of convoy HG 66 (11th war patrol).

For the daily positions of HrMs O 21 during this patrol see the map below.


HrMs O 21 11th war patrolclick here for bigger map

1 Jul 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN), HMS Azalea (Lt. G.C. Geddes, RNR) and HMS Stella Carina (Lt. J.V. Lobb, RANVR) depart from convoy HG 66 to join convoy OG 66.

A few hours later O 21 was ordered to establish a patrol off Cape Finisterre, Spain and leaves the formation.

3 Jul 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived in her patrol position.

6 Jul 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from her patrol area for Gibraltar.

8 Jul 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Gibraltar.

16 Jul 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Gibraltar for her 12th war patrol (1st in the Mediterranean). She is to patrol in the Tyrrhenian Sea.

For the daily and attack positions of HrMs O 21 during this patrol see the map below.


HrMs O 21 12th war patrolclick here for bigger map

29 Jul 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) attacks an Italian convoy about 60 nautical miles South-West of Naples, Italy in position 39°51'N, 13°46'E. Four torpedoes were fired. 2 hits were claimed but in fact all torpedoes fired missed.

(All times are zone -1)
1215 hours - Heard HE bearing 184°.

1309 hours - Sighted smoke bearing 180°.

1401 hours - Sighted one aircraft bearing 175°.

1451 hours - Sighted mast. Started attack. The convoy was later seen to be made up of five merchant vessels of 4000 to 5000 tons each and two Lampo class destroyers as escort.

1515 hours - Heard the HE of what was thought to be a third destroyer.

1553 hours - Fired four torpedoes from 4500 yards at two of the merchant ships. Seven minutes after firing a double explosion was heard. O 21 went to a depth of 35 meters and retired to the South-West upon firing so the results were not observed.

1609 to 1701 hours - 24 Depth charges were dropped by two of the destroyers. O 21 went to 87 meters.

1715 hours - Heard the last HE fade out. Returned to 40 meters.

2130 hours - Surfaced. Nothing in sight.

The convoy attacked had left Tripoli on 27 July and arrived at Naples on 30 July and was made up of the Italian merchants Ernesto (7399 GRT, built 1914), Nita (6803 GRT, built 1913), Nirvo (5270 GRT, built 1919), Aquitania (4971 GRT, built 1924), Palmaiola (1961 GRT, built 1918) and tanker Castelverde (6958 GRT, built 1921). Escorts were Italian destroyers Folgore, Saetta, Fulmine and (possibly) torpedo boat Giuseppe Sirtori.

3 Aug 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) attacks and damaged an Italian barquentine with gunfire South-East of Cagliari, Sardinia, Italy near position 38°47'N, 09°21'E. A torpedo was fired first but it ran under so O 21 surfaced and engaged with gunfire.

(All times are zone -1)
1836 hours - Sighted a three-mast schooner (estimated size, 300 tons) bearing 208°, distance 9000 yards. Started attack.

1913 hours - Fired one torpedo from 1500 yards. It ran under her stern.
Surfaced and engaged the target with gunfire. Range 1200 to 1500 yards. 25 Rounds were fired for at least seven hits, five in the engine room and two on the forecastle. Broke off the action at 2045 hours owning to the darkness fearing that MAS boats were also in the area and could attack O 21 unobserved.

Supermarina War Diaries mention that a vessel belonging to the Cagliari harbour defence was attacked at 2130 hrs but does not specify name or damage (if any).

6 Aug 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) ended her 12th war patrol at Gibraltar.

27 Aug 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Gibraltar for her 13th war patrol (2nd in the Mediterranean). She is to patrol in the Tyrrhenian Sea.

For the daily and attack positions of HrMs O 21 during this patrol see the map below.


HrMs O 21 13th war patrolclick here for bigger map

31 Aug 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) attacks the Italian submarine Emo with two torpedoes about 70 nautical miles East-South-East of Cagliari, Sardinia, Italy in position 38°53'N, 10°38'E. Both torpedoes missed their target.

(All times are zone -1)
0555 hours - Sighted Italian submarine (thought to be Marcello-class) bearing 280°. Started attack.

0618 hours - Fired bow tubes 1 and 3 from 2200 yards. No hits were obtained. It was intended to fire four torpedoes but O 21 lost depth control during the attack.

0625 hours - Heard one explosion. HE ceased.

0635 hours - HE was heard again. Started reloading tube 1 and 3.

According to Italian sources submarine Emo was returning home after operating in the Atlantic, she witnessed a torpedo track passing 1000 meters astern followed by an explosion.

1 Sep 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) sights a convoy of three merchant ships about 40 nautical miles North of Isola di Ustica, Italy in position 39°19'N, 13°21'E. As the ships turned out to be Vichy French they were not attacked.

(All times are zone -1)
1518 hours - Sighted three big ships right ahead, distance 7 nautical miles. Started attack. Two of the ships were later seen to have three funnels, the other ship had two funnels.

1618 hours - Ended attack on convoy as the ships were seen to be Vichy French. The ships are thought to be the following vessels:
D'Artagnan (passenger / cargo ship, 15105 GRT, built 1925)
Champollion (passenger ship, 12263 GRT, built 1925)
Massilia (passenger / cargo (reefer) ship, 15147 GRT, built 1920).
They appeared to be heading towards the Straits of Messina.

Note: D?Artagnan was at Saigon at that time so she could not be one of the ships sighted by O 21.

3 Sep 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) sights a convoy of three merchant ships about 60 nautical miles North-North-East of Isola di Ustica, Italy near position 39°45'N, 13°32'E. As the ships turned out to be Vichy French they were not attacked.

(All times are zone -1)
0643 hours - Heard HE bearing 150°.

0715 hours - Sighted smoke bearing 160°. Started attack.

0755 hours - Sighted three ships.

0815 hours - Identified the ships as Vichy-French. Stopped attack. Convoy appeared to come from the Straits of Messina and steering for Strait Bonifacio.

5 Sep 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) torpedoed and sank the Italian merchant Isarco (5738 GRT, built 1924) about 30 nautical miles south-west of Isola d'Ischia, Italy in position 40°12'N, 13°17'E.

(All times are zone -1)
0025 hours - Sighted dark shape and smoke to the South-West. Distance 7 nautical miles. Started attack.

0035 hours - Submerged and continued attack.

0120 hours - Fired 2 torpedoes on merchant vessel from 900 yards. Both torpedoes hit, one beneath the bridge and one near the after hatch.

0124 hours - Surfaced and picked up 22 survivors.

6 Sep 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) attacks an Italian convoy with two torpedoes about 50 nautical miles East of La Maddalena near position 41°05'N, 10°20'E. No hits are obtained.

(All times are zone -1)
0405 hours - Sighted ship bearing 340°. Later it was seen that it was one of two merchant ships in a convoy that was escorted by an Armed Merchant Cruiser.

0420 hours - Submerged and started attack.

0428 hours - Fired two torpedoes from 700 yards. Went to 35 meters. The rear ship went directly overhead. Returned to periscope depth to try to take a stern shot at this ship but this was not possible. No hits were obtained with the two torpedoes fired.

7 Sep 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) attacks what is thought to be an Italian minelayer of the Fasana class about 20 nautical miles East of La Maddalena near position 41°09'N, 09°54'E.

(All times are zone -1)
0105 hours - Sighted ship bearing 090°.

0118 hours - Submerged but lost target out of sight.

0140 hours - Surfaced, but remained trimmed down.

0150 hours - Sighted target again bearing 210°. Made end around to get ahead of the target.

0420 hours - Submerged. Started attack.

0453 hours - Fired one torpedo from 500 yards. Missed. The target was now thought to be a minelayer of the Fasana class so the torpedo most likely ran under. Retired to the South-East.

8 Sep 1941
While on patrol near Cagliari Bay HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) tries to attack an Italian convoy but fails to do so about 5 nautical miles East of Isola Serpentara near position 39°09'N, 09°43'E.

Later O 21 fired her last remaining torpedo at another Italian convoy about 15 nautical miles South-East of Isola dei Cavoli near position 38°54'N, 09°50'E. The torpedo missed.

(All times are zone -1)
1145 hours - Sighted two ships bearing 023°. An Cant. Z501 aircraft was overhead. Started attack. The ships were thought to be an Asmara-type cargo vessel escorted by an armed merchant cruiser type Citta di Napoli.

1307 hours - Could not close the distance to less than 4000 yards. Concluded that attack had failed and don't fire the last remaining torpedo. Proceeded Southwards. Ships were later seen to enter Cagliari Bay.

------------------------------------------------

1800 hours - Sighted ship bearing 265°. Distance 7000 yards. Started attack. Soon more ships were sighted. The convoy was made up of an armed merchant cruiser type Citta di Napoli (possibly the same ship sighted earlier today), one small tanker (3000 tons) and two merchant vessels (7000 and 4000 tons).

1929 hours - Fired one torpedo (the last) from 1000 yards at the 7000 tons merchant vessel. Missed. Set course to the South-West.

12 Sep 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) ended her 13th war patrol at Gibraltar.

21 Sep 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Gibraltar for her 14th war patrol (3rd in the Mediterranean). She is to patrol in the Tyrrhenian Sea, off the East Coast of Sardinia.

For the daily and attack positions of HrMs O 21 during this patrol see the map below.


HrMs O 21 14th war patrolclick here for bigger map

3 Oct 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) torpedoed and sank the Vichy-French merchant Oued Yquem (1369 GRT, built 1920) east of Cape Figari, Sardinia, Italy in position 40°58'N, 09°59'E.

(All times are zone -1)
1000 hours - Sighted smoke bearing 286°. Started attack.

1253 hours - Fired two torpedoes from 900 yards. The first torpedo ran on the surface. The second torpedo hit the ships stern. The ship was seen to sink in three minutes, stern first with the bow rising vertically into the air.

The crew of 30 (including three wounded) were later picked up according to Italian sources.

8 Oct 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) ended her 14th war patrol at Gibraltar.

22 Oct 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) is docked at Gibraltar.

27 Oct 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) left dock.

7 Nov 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) conducts exercises off Gibraltar with HMS Wishart (Cdr. H.G. Scott, RN) and aircraft from HMS Ark Royal (Capt. L.E.H. Maund, CBE, RN) and HMS Malaya (Capt. C. Coppinger, DSC, RN).

9 Nov 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Gibraltar for her 15th war patrol (4th in the Mediterranean). She is to patrol in the Tyrrhenian Sea.

For the daily and attack positions of HrMs O 21 during this patrol see the map below.


HrMs O 21 15th war patrolclick here for bigger map

15 Nov 1941
While on patrol in the Tyrrhenian Sea HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) attacks the Italian merchant Ninetto G. (5355 GRT, built 1913) off Fiumicino, Italy in position 41°47'N, 12°06'E. All torpedoes fired missed their target.

(All times are zone -1)
1530 hours - Sighted three ships bearing 140°. The convoy consisted of one empty tanker of about 5000 tons and two merchant vessels of about the same size. They were in single line ahead. 1000 Yards on the beam on the port side there was a Lampo-class destroyer. Course of the convoy was 315°, speed 8 knots.

1535 hours - Sighted a flying boat type Cant Z 501 that was escorting the convoy. Started attack.

1605 hours - Sighted, at a distance of 500 yards, a torpedo boat of the Abba-class. It was followed by a laden modern tanker of about 5000 tons. O 21 went deep as the Lampo class destroyer hoisted a flag signal and turned towards. 1620 hours - The torpedo boat turned to the North and joined the Northbound convoy.

1626 hours - In position 41°47'N, 12°06'E fired two torpedoes against one of the 5000 tons merchants. O 21 broke surface after venting of the first torpedo tube failed. It was intended to fire a third torpedo but this one was not fired. O 21 dived again and went to 60 meters, later to 40 meters.

1636 hours - The torpedo boat dropped its first depth charges. They were very close.

1656 hours - The torpedo boat dropped its last depth charge and later made off to the North.

According to Italian sources the above mentioned Ninetto G. was in convoy with merchant Valsavoia (5733 GRT, 1919) proceeding to La Spezia escorted by the torpedo-boat Giacinto Carini.
Carini had just been escorting the southbound tanker Iridio Mantovani (10540 GRT, built 1939) and had met the northbound Ninetto G. and Valsavoia escorted by the torpedo-boat Perseo. The two convoys had just exchanged escort.

16 Nov 1941
While on patrol in the Tyrrhenian Sea HrMs O 21 (Lt.Cdr. J.F. van Dulm) attacks the Italian merchant Itu (1578 GRT, built 1895) off the East coast of Sardinia about 7 nautical miles East of Cala Gonone in position 40°15'N, 09°45'E. All torpedoes fired missed their target.

(All times are zone -1)
0727 hours - In position 40°15'N, 09°45'E heard HE and sighted ship bearing 230°. It was a grey dazzle painted merchant vessel of about 3000 tons, course 010°, speed 8 knots, distance 4500 yards. The camouflage of the ship made it very difficult to see against the background. Started attack.

0741 hours - Fired two torpedoes from 2000 yards. As the ship was seen to evade the torpedo tracks these must have been seen.

21 Nov 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) attacks a liner in a convoy about 15 nautical miles South-West of Civitavecchia, Italy in position 41°55'N, 11°27'E. Two torpedoes were fired but no hits were obtained.

(All times are zone -1)
0645 hours - Heard HE bearing 110°.

0705 hours - Sighted a medium seized merchant vessel on a course of 300°. Started attack.

0710 hours - The ship now proved to be a heavily zigzagging Armed Merchant Cruiser belonging to a convoy of 2 medium seized merchant ships and 1 liner that was escorted by 2 AMC's. General course of the convoy was 045°.

0715 hours - Dived to a greater depth as a Cant Z 501 flying boat passed overhead just after the nearest AMC had hoisted a pendant. Returned to periscope depth shortly afterwards.

0739 hours - Fired two torpedoes at the liner from 1800 yards. Went deep. No hits were obtained.

0810 hours - The convoy was now out of sight.

This liner might have been Citta di Trieste (4785 GRT, built 1915) but as of yet (January 2012) this cannot be confirmed. This will have to be researched further at the Ufficio Storico in Rome, Italy in the future.

22 Nov 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) sank the Italian schooner San Salvatore (92 GRT) with gunfire in the central Tyrrhenian Sea in position 41°20'N, 10°33'E.

(All times are zone -1)
2134 hours - Sighted ship bearing 125°. The ship proved to be a 2-mast schooner of about 500 tons.

2145 hours - Opened fire with the deck gun. The crew abandoned ship with their small boat after the first round.

2210 hours - The schooner was seen to sink bow first after 47 rounds.

23 Nov 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) about 25 nautical miles South of Isola del Giglio in position 41°56'N, 10°50'E fires two torpedoes against a contact obtained by HE (Hydrophone Effect) alone. No ship was seen. Both torpedoes failed to hit their unknown target.

(All times are zone -1)
0028 hours - Heard HE bearing 053°.

0205 hours - In position fired two torpedoes from the deck tubes at the very distinct loud HE. The target was not seen. No hits were obtained.

24 Nov 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) sank an Italian schooner with gunfire off the east coast of Sardinia, Italy about 30 nautical miles South-East of La Maddalena in position 40°56'N, 10°23'E. This was most likely the Nuovo Sant'Antonio (52 GRT) that disappeared without a trace at this time during a trip from Civitavecchia to Arbatax.

(All times are zone -1)
0150 hours - Sighted a weak light bearing 100°.

0200 hours - Discovered the silhouette of a small ship.

0222 hours - Attacked a small two-masted schooner of about 250 tons with gunfire. The crew took to their small boat after the first rounds.

0238 hours - After 21 rounds she was still afloat. One mast was shot away. The ship was then sunk by ramming as there was no more ammunition for the deck gun.

It is often stated that the schooner sunk in this attack was the Unione (216 GRT). This schooner however had foundered in bad weather on 21 November.

28 Nov 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) ended her 15th war patrol at Gibraltar.

28 Nov 1941
German U-boat U-95 was sunk in the western Mediterranean, about 100 nautical miles east-north-east of Gibraltar in position 36°24'N, 03°20'W by the Dutch submarine HrMs O 21. (Lt.Cdr. J.F. van Dulm, RNN).

O 21 arrived at Gibraltar later on the same day.

For an eyewitness account on this encounter between these two submarines see this website (offsite link).

(All times are zone -1)
0035 hours - Sighted a suspicious silhouette bearing 085°. Stopped zigzagging and increased speed to 17 knots. It was thought that the dark shape was either a submarine of a motor launch.

0044 hours - The suspicious ship flashed with a dimmed signal lamp.

0048 hours - The contact again flashed the challenge. It was recognised as German by the British signalman. Reduced speed to 15 knots.

0050 hours - Fired both stern tubes in short succession. The first torpedo missed and the enemy turned away just as Lt.Cdr. van Dulm had thought he would do. The first torpedo had no effect as it passed close to the enemy's starboard site. The second one had the desired effect as it hit the U-boat abaft the conning tower and blew the stern off. The U-boat was seen to sink by the stern at an angle of 45°.

0112 hours - O 21 now proceeded to where the enemy sank to collect evidence of this sinking when survivors were noticed in the water. 12 Survivors were picked up including the Commanding Officer.

The Germans had sighted O 21 first but as the silhouette of the Dutch submarine looked like a German U-boat a challenge was made. The quick reaction of Lt.Cdr. van Dulm surprised the Germans.

5 Dec 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Gibraltar bound for the U.K. where she is to refit.

For the daily and attack positions of HrMs O 21 during the passage to the U.K. see the map below.


HrMs O 21 passage Gibraltar - U.K.click here for bigger map

12 Dec 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Holy Loch.

16 Dec 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Holy Loch for her 16th war patrol. Her refit is postponed as every submarine available is to be used to patrol off Brest, France. The British are under the impression that the German heavy ships there are about to sortie into the Atlantic Ocean.

For the daily positions of HrMs O 21 during this patrol see the map below.


HrMs O 21 16th war patrolclick here for bigger map

24 Dec 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived and ended her 16th war patrol at Milford Haven. It is decided after consulting experts that O 21 is not fit for further patrols due to problems with the electric motors.

27 Dec 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Milford Haven for Dundee.

29 Dec 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Dundee.

30 Dec 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Dundee for Rosyth.

31 Dec 1941
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrive at Rosyth to remove her battery.

13 Jan 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) is towed from Rosyth to Grangemouth where she is to refit.

18 Feb 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) is docked at Grangemouth where she is undergoing a refit.

12 May 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) leaves the dock at the Grangemouth dockyards where she is undergoing refit.

10 Jun 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) is docked again at Grangemouth for some modifications to the torpedo tubes.

17 Jun 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) left dock.

1 Jul 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) ended her refit at Grangemouth. She moved to Rosyth on this day.

2 Jul 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) moves from Rosyth to Leith.

3 Jul 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) moves from Leith to Dundee.

4 Jul 1942
From 4 to 15 July 1942, HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) conducts trials and exercises out of Dundee.

16 Jul 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Dundee for Holy Loch. She is escorted by HrMs Jan van Gelder (Lt. P.L.M. van Geen, RNN)

19 Jul 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Holy Loch for a period of trials and exercises.

2 Aug 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) is docked at Kames Bay, Cumbrae Island.

3 Aug 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) left dock and returns to Holy Loch for more trials and exercises.

12 Aug 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Holy Loch for Gibraltar. This is the first leg of the trip to the Far East where she is to join the Eastern Fleet.

For the daily and attack positions of HrMs O 21 during the passage to the Far East see the map below.


HrMs O 21 passage U.K. - Far Eastclick here for bigger map

16 Aug 1942
While on passage from Holy Loch to Gibraltar HrMs O 21 (Lt.Cdr. J.F. van Dulm) fired four torpedoed against German U-boat U-254 about 200 nautical miles North-West of Cape Finisterre in approximate position 46°39'N, 12°05'W.

1630 hours - Head HE bearing 250°.

1645 hours - Sighted u-boat, 500 tons type, on an Easterly course.

1707 hours - Fired four torpedoes from 3500 yards. Two torpedoes ran on the surface so were easily spotted aboard the U-boat who turned away.

20 Aug 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Gibraltar.

8 Sep 1942
After some repairs HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Gibraltar for Freetown.

16 Sep 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Freetown.

23 Sep 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Freetown for Pointe Noire.

2 Oct 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Pointe Noire.

3 Oct 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Pointe Noire, Congo for Simonstown, South Africa.

12 Oct 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Salandha Bay, South Africa. En-route from Pointe Noire O 21 was ordered to proceed to Salandha Bay instead of Simonstown due to the threat of German U-boats that were operating in South African waters at that time.

16 Oct 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Salandha Bay for Simonstown.

17 Oct 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Simonstown. At Simonstown defective machinery (Vulcan clutch for port main engine) is removed and replaced by a Vulcan clutch from HrMs O 19 (Lt.Cdr. H.F. Bach Kolling, RNN(R) that is also in Simonstown en-route from the Far East to the U.K. to be refitted.

7 Dec 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) is docked at Simonstown.

15 Dec 1942
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) left dock.

11 Jan 1943
During 11 and 12 January 1943 HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) conducts trials of Simonstown. She is escorted by HMS Genista (Lt.Cdr. R.M. Pattinson, DSC, RNR).

15 Jan 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) conducts A/S exercises off Simonstown with HMS Rockrose (Lt. E.J. Binfield, DSC, RNR), HMSAS Vereeniging and HMSAS Sonnebloem.

16 Jan 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Simonstown for East London. She is escorted by HMS Rockrose (Lt. E.J. Binfield, DSC, RNR).

18 Jan 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) and her escort HMS Rockrose (Lt. E.J. Binfield, DSC, RNR) arrive at East London. En-route A/S exercises were carried out with Rockrose and aircraft.

24 Jan 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from East London for Diego Saurez. Upon leaving East London A/S exercises were carried out with HMS Sondra (T/Lt. W.P. Hart, RNR).

1 Feb 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Diego Saurez.

4 Feb 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) conducts A/S exercises of Diego Saurez with HMIS Khyber (Lt. B.S. Soma, RIN), HMS Lurched (T/Lt. J. Muir, RNVR) and HMS Mastiff (ii) (T/Lt. C.M. Motherwell, RNVR).

5 Feb 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) conducts A/S exercises of Diego Saurez with HMS Lurched (T/Lt. J. Muir, RNVR) and HMS Mastiff (ii) ((T/Lt. C.M. Motherwell, RNVR).

6 Feb 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) conducts A/S exercises of Diego Saurez with HMS Lurched (T/Lt. J. Muir, RNVR) and HMS Mastiff (ii) ((T/Lt. C.M. Motherwell, RNVR).

9 Feb 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Diego Saurez for Addu Atoll.

16 Feb 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Addu Atoll.

18 Feb 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) conducts A/S exercises of Diego Saurez with HMS Balta (T/Lt. J.A.H. Punting, RNR).

After these exercises O 21 departed from Addu Atoll for Colombo.

21 Feb 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Colombo.

6 Mar 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Colombo for her 17th war patrol (1st in the Far East). She was ordered to patrol in the Andaman Sea to guard the approach to Port Blair.

For the daily and attack positions of HrMs O 21 during this patrol see the map below.


HrMs O 21 17th war patrol weergeven op een grotere kaart

13 Mar 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) torpedoed and sank the Japanese merchant cargo ship Kasuga Maru No.2 (3967 GRT, built 1936) off Port Blair, Andaman Islands in position 11°39'N, 92°49'E.

(All times are zone -6.5)
0720 hours - The cargo ship that was sighted yesterday was seen moving around the bay as if to leave Port Blair. Prepared to attack.

0730 hours - The ship was seen to leave the bay. The size of the ship was estimated at 4000 tons.

0750 hours - In position 11°39'N, 92°49'E fired four torpedoes from 1400 yards. Two hits were obtained and the ship sank in five minutes. O 21 retired to the South-East. Two small enemy motor launches left the harbour to hunt the submarine but they were unsuccessful.

24 Mar 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) ended her 17th war patrol (1st in the Far East) at Colombo.

9 Apr 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) conducts A/S exercises near Colombo with HMAS Tamworth (T/Lt. W.H. Deans, RANR(S)).

11 Apr 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Colombo for her 18th war patrol (2nd in the Far East). She was ordered to patrol in the Malacca Straits. A special operation is also to be carried out.

For the daily and attack positions of HrMs O 21 during this patrol see the map below.


HrMs O 21 18th war patrolclick here for bigger map

18 Apr 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) conducts Special operation 'May'. Two groups of four men each were landed on the Malayan coast to the South of the Sembilan Islands.

22 Apr 1943
HrMs O 21. (Lt.Cdr. J.F. van Dulm) torpedoed and sank the Japanese army cargo ship Yamazato Maru (6925 GRT, built 1937) in the Malacca Strait in position 03°26'N, 99°48'E.

A few hours later an attack on another Japanese ship in position 03°23'N, 100°07'E failed to produce any hits.

(All times are zone -6.5)
0045 hours - In position 03°07'N, 100°40'E sighted the silhouette of a ship bearing 182°.

0047 hours - Dived. HE was picked up.

0135 hours - HE was still being picked up but became weaker.

0151 hours - Surfaced and sighted a ship bearing 251°, distance 7 nautical miles.

0350 hours - Sighted an escort vessel ahead of the main target.

0500 hours - Dived at dawn.

0511 hours - The target was seen to be a large camouflaged merchant ship of about 7000 tons. The escort was thought to be a Chidori-class torpedo boat. Started attack.

0540 hours - In position 03°26'N, 99°48'E fired four torpedoes from 2000 yards resulting in two hits. One just in front of the bridge and one in hold number 5. The ship broke in two with the front part capsizing and sinking slowly. The aft part burst into flames and sank quickly.

0601 hours - The torpedo boat dropped a pattern of four depth charges but these were not close. O 21 retired to the East-North-East.

0830 hours - The torpedo boat was now lost out of sight.

-----------------------------------------

1110 hours - In position 03°28'N, 100°03'E sighted a ship bearing 090°. Started attack with the deck torpedo tubes but one of the doors could not be opened properly so abandoned this plan and went for an attack with the stern torpedo tubes.

1149 hours - In position 03°23'N, 100°07'E fired two stern torpedoes at the target that was thought to be of about 2000 tons. Range 700 yards. The torpedoes missed. It appeared the target saw the tracks and avoided. She altered course and made for the submarine.

1152 hours - The ship dropped three depth charges about 300 yards away. O 21 took avoiding action.

1202 hours - Two more depth charges were dropped about 1000 yards away. O 21 cleared the area to the North.

1246 hours - Two more depth charges were dropped 1800 yards away.

1300 hours - Saw an aircraft circling the area. Went to 75 feet and came to periscope depth every 20 minutes.

1315 hours - Saw a torpedo boat, Chidori-type and most likely the same one as this morning joining the hunt.

1500 hours - Nothing in sight now.

29 Apr 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) ended her 18th war patrol (2nd in the Far East) at Colombo.

7 May 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) is docked at Colombo.

10 May 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) left dock.

28 May 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Colombo for her 19th war patrol (3rd in the Far East). She was ordered to patrol in the Northern end of the Malacca Straits.

18 Jun 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) ended her 19th war patrol (3rd in the Far East) at Colombo.

For the daily positions of HrMs O 21 during this patrol see the map below.


HrMs O 21 19th war patrolclick here for bigger map

9 Jul 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Colombo for Exmouth Gulf, Australia.

For the daily and attack positions of HrMs O 21 during the passage to Exmouth Gulf see the map below.


HrMs O 21 passage Colombo - Exmouth Gulfclick here for bigger map

20 Jul 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Exmouth Gulf, Australia.

23 Jul 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Exmouth Gulf for her 20th war patrol. She is to conduct several special operations (under the control of the Dutch NEFIS organisation) off the South coast of Java and Bali and also to the North of Bali and in the Kangean Archipaligo.

The positions of O 21 are 'coded' in the ships log. The ships positions were 'decoded' by us with help of a report in Dutch language on this patrol (No report in English has been found in Dutch or British archives.)

For the daily and attack positions of HrMs O 21 during this patrol see the map below.


HrMs O 21 20th war patrolclick here for bigger map

27 Jul 1943
In the period 27 July to 29 July HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) is to make rendez-vouz off Pulau Sempoe (now Sumbermanjing) with a small sailing vessel carrying an agent. However no sailing vessel displaying the secret markings that were agreed shows up.

31 Jul 1943
During the afternoon HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) performs a periscope reconnaissance of the airfield near Kuta, Bali.

1 Aug 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) lands an agent near Pang Pang Bay on the South-East tip of Java (In Strait Bali).

(All times are (most likely) zone -8)
0430 hours - Sighted the lading area.

0542 hours - Dived. Stayed off the bay during the day.

1945 hours - Surfaced.

2020 hours - Land party no. 2 (3 members of the crew of O 21) to reconnoitre a possible landing area.

2215 hours - The party returned. They had not seen any Japanese.

2245 hours - Party no. 1 and agent '289' were landed.

0100 hours (2nd) - Party no 1 returned.

2 Aug 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) lands a party (party No. 2) to reconnoitre a possible landing place in the Pang Pang Bay. They are back on board after nearly 2 hours.

(All times are (most likely) zone -8)
0550 hours - Dived and returned to the Pang Pang Bay. It was not possible to enter the bay due to the bad visibility.

1600 hours - Enter the bay.

1830 hours - Bottomed in 14.5 meters of water.

1920 hours - Surfaced.

2015 hours - Land party no. 2 to reconnoitre the landing area. Two small fishing vessels are laying on the beach nearby.

2150 hours - Party no. 2 returned. They had seen no Japanese.

3 Aug 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) lands a party (party No. 2) to reconnoitre a possible landing place near the Pang Pang Bay. They are back on board after 1 hour.

Shortly afterwards party No. 1 departed from O 21 in their rubber boat to pick up the agent landed on 1 August. He does not show up and the landing party also don't return to O 21 at the agreed time.

(All times are (most likely) zone -8)
0550 hours - Dived and remain North of the Pang Pang bay.

1200 hours - Entered the bay.

1415 hours - Bottomed at 13 meters inside the bay. Kept periscope watch for a small sailing vessel that showed the agreed markings. None however was seen during the day.

1915 hours - Surfaced.

2000 hours - Landed party no. 2 to check one of the landing areas.

2100 hours - The party returned they had sighted nothing.

2130 hours - Sent landing party no. 1 to the place where the agent was landed two day previously. They were soon lost out of sight in the diminishing visibility.

2145 hours - Signals were sighted on the shore but these could not be read due to the bad visibility. They were thought to be from the landing party. Later it was thought they must have been made by agent '289'.

2300 hours - The signals were still seen on the same place. Signals from O 21 were however not answered. Due to the further diminishing visibility contact was lost around midnight.

0115 hours (4th) - As it was thought that the dinghy of party no. 1 was lost it was decided to sent party no. 2 to look for them.

0400 hours (4th) - Party no. 2 returned. They were unable to find party no. 1.

0410 hours (4th) - O 21 departed the bay.

0546 hours (4th) - Dived.

4 Aug 1943
During the afternoon the lost party no. 1 is spotted on a beach in the Pang Pang Bay. Contact was established and after dark they were able to return to the O 21. The agent they were to pick up was however not seen again.

(All times are (most likely) zone -8)
1100 hours - Set course towards the entrance to the bay.

1330 hours - Entered the bay. Sighted party no. 1 on a beach. Signalled with the periscope. Signals were answered. It was agreed that they were to be picked up after dark.

1520 hours - Bottomed in 12 meters of water.

1915 hours - Surfaced and sent party no. 2 to the shore to pick up party no. 1.

2000 hours - Both party's returned to the submarine. During the remainder of the evening O 21 tried to establish contact with agent '289', All attempts were however unsuccessful.

2300 hours - Left the bay.

5 Aug 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) passes through Lombok Strait Northwards.

6 Aug 1943
In the period 6 August to 8 August HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) is to make rendez-vouz off Goa Goa (now Goa-Daja) with a small sailing vessel carrying an agent. However no sailing vessel displaying the secret markings that were agreed shows up. A small sailing vessel that was thought to show one of the secret markings was stopped on the 7th but as this proved to be a native fishing vessel it was released.

9 Aug 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) performs a periscope reconnaissance of the North-West coast of Bali.

10 Aug 1943
In the early morning hours HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) lands party no. 2 on Hertenbeest (Deer) Island, that lays off the North-West coast of Bali. They are to spot aircraft movements during the day.

After dark they were taken off again. They had also shot a deer and brought with them fresh meat for two days.

12 Aug 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at a rendez-vouz off Tandjung Djankar, Java (now Jangkar). No small sailing vessel with the agreed markings shows up.

After dark O 21 is detected and depth charged by a Japanese A/S vessel at the Eastern entrance to Strait Madura near position 07°32'S, 114°18'E.

(All times are (most likely) zone -8)
1945 hours - Sighted ship shape bearing 285°.

1955 hours - Thought to have seen lights in the same direction.

2015 hours - The ship is lost out of sight, but picked up again shortly afterwards. They had turned towards and were rapidly closing.

2020 hours - The ship signalled and then opens fire with a machine gun.

2022 hours - Dived.

2025 - 2028 hours - Nine depth charges were dropped.

2040 hours - Three more depth charges were dropped.

2400 hours - HE faded out bearing 128°. One hour later O 21 surfaces to find nothing in sight.

13 Aug 1943
During the evening HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) is detected and depth charged by a Japanese A/S trawler South of Kangean Island near position 07°03'S, 115°20'E. Minor damage is sustained but O 21 manages to escape on the surface after dark.

(All times are (most likely) zone -8)
1908 hours - Surfaced.

1932 hours - Due to a lightning bolt sighted a ship with two masts and one funnel.

1934 hours - Dived. No HE was picked up.

1950 hours - Nothing could be sighted through the periscope.

1955 hours - Strange noises were picked up on Asdic. Shortly afterwards HE was picked up from a ship crossing shortly ahead from Starboard to Port.

1958 hours - 4 depth charges explode near the bow causing minor damage.

2030 hours - No HE heard anymore.

0025 hours (14th) - Nothing in sight so surfaced.

0030 hours (14th) - Sighted Japanese A/S trawler 5 nautical miles away.

0034 hours (14th) - The trawler is seen to increase speed and turn towards. O 21 also increased speed to outrun the trawler on the surface.

0045 hours (14th) - The trawler was no longer in sight. Shortly before 0200 hours (14th) she was sighted again but after a change of course she was lost out of sight not to be seen again.

16 Aug 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) passes through Lombok Strait Southwards.

20 Aug 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) ended her 20th war patrol (4th in the Far East) at Exmouth Gulf.

21 Aug 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Exmouth Gulf for Fremantle.

24 Aug 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Fremantle. O 21 has some problems with her diesel engines.

6 Sep 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) is put on the slip at Fremantle.

11 Sep 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) is put back in the water.

1 Oct 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) conducts exercises near Fremantle with HrMs Tjerk Hiddes (Lt.Cdr. W.J. Kruys, RNN)

14 Oct 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) conducts A/S exercises near Fremantle with yacht USS Isabel.

15 Oct 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) conducts A/S exercises near Fremantle with HMAS Dubbo (T/Lt. N.G. Weber, RANR(S)).

28 Nov 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Fremantle for Colombo. It is decided that she is to return to the U.K. for a refit.

For the daily and attack positions of HrMs O 21 during the passage to the U.K. see the map below.


HrMs O 21 passage Fremantle, Australia - Dundee, U.K.click here for bigger map

11 Dec 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Colombo.

30 Dec 1943
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Colombo for Aden.

8 Jan 1944
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Aden.

9 Jan 1944
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Aden for Port Said.

14 Jan 1944
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Suez.

15 Jan 1944
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) transits the Suez Canal and arrived at Port Said.

22 Jan 1944
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Port Said for Malta.

27 Jan 1944
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Malta.

31 Jan 1944
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Malta, she joins convoy GUS-29 for the passage to Gibraltar.

5 Feb 1944
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Gibraltar.

10 Feb 1944
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) departed from Gibraltar for the U.K.

22 Feb 1944
HrMs O 21 (Lt.Cdr. J.F. van Dulm, RNN) arrived at Dundee. At Dundee the battery will be removed and a new battery is installed. It has been decided that O 21 is to refit in the U.S.A.

7 Apr 1944
HrMs O 21 (Lt. F.J. Kroesen, RNN) departed from Dundee for Holy Loch.

10 Apr 1944
HrMs O 21 (Lt. F.J. Kroesen, RNN) arrived at Holy Loch.

28 Apr 1944
HrMs O 21 (Lt. F.J. Kroesen, RNN) is docked at Holy Loch.

3 May 1944
HrMs O 21 (Lt. F.J. Kroesen, RNN) left dock.

6 May 1944
HrMs O 21 (Lt. F.J. Kroesen, RNN) departed from Holy Loch for St. John's, Newfoundland, Canada.

For the daily positions of HrMs O 21 during the passage to the U.S.A. see the map below.


HrMs O 21 passage Holy Loch (UK) - Portsmouth (USA)click here for bigger map

17 May 1944
HrMs O 21 (Lt. F.J. Kroesen, RNN) arrived at St. John's.

20 May 1944
HrMs O 21 (Lt. F.J. Kroesen, RNN) departed from St. John's for Halifax.

22 May 1944
HrMs O 21 (Lt. F.J. Kroesen, RNN) arrived at Halifax.

23 May 1944
HrMs O 21 (Lt. F.J. Kroesen, RNN) departed from Halifax for New London, Connecticut, U.S.A.

25 May 1944
HrMs O 21 (Lt. F.J. Kroesen, RNN) arrived at New London.

27 May 1944
HrMs O 21 (Lt. F.J. Kroesen, RNN) departed from New London for New York where she arrived later the same day.

28 May 1944
HrMs O 21 (Lt. F.J. Kroesen, RNN) departed from New York for Philadelphia where she is to refit at the Navy Yard.

29 May 1944
HrMs O 21 (Lt. F.J. Kroesen, RNN) arrived at the Philadelphia Navy Yard.

17 Dec 1944
With her refit completed and after some trials HrMs O 21 (Lt. F.J. Kroesen, RNN) departed from the Philadelphia Navy Yard for New London.

18 Dec 1944
HrMs O 21 (Lt. F.J. Kroesen, RNN) arrived at New London for a period of trials and training.

9 Feb 1945
With her trials, training and modifications completed HrMs O 21 (Lt. F.J. Kroesen, RNN) departed from New London for the Panama Canal. This is the first leg of the trip to Australia.

For the daily positions of HrMs O 21 during the passage to Australia see the map below.


HrMs O 21 passage New London (U.S.A.) - Fremantle (Australia)click here for bigger map

19 Feb 1945
HrMs O 21 (Lt. F.J. Kroesen, RNN) arrived at Balboa, Panama.

2 Mar 1945
HrMs O 21 (Lt. F.J. Kroesen, RNN) departed from Balboa for the Galapagos Islands.

6 Mar 1945
HrMs O 21 (Lt. F.J. Kroesen, RNN) topped up with fuel at Seymour Island, Galapagos Islands before proceeding towards Bora Bora, French Polynesia.

22 Mar 1945
HrMs O 21 (Lt. F.J. Kroesen, RNN) arrived at Bora Bora, French Polynesia.

25 Mar 1945
HrMs O 21 (Lt. F.J. Kroesen, RNN) departed from Bora Bora for Wellington, New Zealand.

6 Apr 1945
HrMs O 21 (Lt. F.J. Kroesen, RNN) arrived at Wellington.

25 Apr 1945
After repairs HrMs O 21 (Lt. F.J. Kroesen, RNN) departed from Wellington for Melbourne, Australia.

3 May 1945
After repairs HrMs O 21 (Lt. F.J. Kroesen, RNN) arrived at Melbourne.

13 May 1945
HrMs O 21 (Lt. F.J. Kroesen, RNN) departed from Melbourne for Fremantle.

20 May 1945
HrMs O 21 (Lt. F.J. Kroesen, RNN) arrived at Fremantle.

7 Jun 1945
HrMs O 21 (Lt. F.J. Kroesen, RNN) is put on the slip at Fremantle.

9 Jun 1945
HrMs O 21 (Lt. F.J. Kroesen, RNN) is put back in the water.

3 Jul 1945
HrMs O 21 (Lt. F.J. Kroesen, RNN) is put on the slip at Fremantle.

4 Jul 1945
HrMs O 21 (Lt. F.J. Kroesen, RNN) is put back in the water.

7 Jul 1945
HrMs O 21 (Lt. F.J. Kroesen, RNN) departed from Fremantle for her 21th war patrol (5th in the Far East, 1st of her 2nd deployment to the Far East). She was ordered to patrol along the South coast of Java and in the Sunda Strait area.

No log is available for this period so unfortunately no map can be displayed.

11 Jul 1945
HrMs O 21 (Lt. F.J. Kroesen, RNN) arrived at Onslow, Australia for fuel and fresh provisions.

12 Jul 1945
After taking on board extra fuel and fresh provision HrMs O 21 (Lt. F.J. Kroesen, RNN) departed from Onslow for her patrol area.

29 Jul 1945
HrMs O 21 (Lt. F.J. Kroesen, RNN) damaged two Japanese coasters with gunfire off the Northern entrance to the Sunda Strait.

(All times are zone -9)
0827 hours - Sighted a small steam vessel bearing 247°, range 3 nautical miles. She was hugging the Sumatra coast and was on a Southerly course.

0844 hours - Surfaced for gun action at 5000 yards. The target beached itself in position 05°49'S, 105°48'E. The crew was seen to abandon ship in a small boat.

0857 hours - After 62 rounds, and several hits, the gun malfunctioned and fire had to be ceased. The target was seen to blow off steam but no fire was observed. O 21 cleared the area to the South-East at speed.

-------------------------------------------

1315 hours - Sighted a 500 tons coaster bearing 265°, range 3.5 nautical miles. She was coast crawling on a Northerly course. O 21 closed and opened fire at 5000 yards. After 23 rounds the gun malfunctioned again and this action had also to be broken off. The target meanwhile was hit several times.

31 Jul 1945
HrMs O 21. (Lt. F.J. Kroesen, RNN) sank a small Japanese fishing vessel with gunfire off the Wijnkoops Bay on the South coast of Java (now Pelabuhan Ratu).

(All times are zone -9)
1730 hours - Sighted a motor fishing vessel bearing 095°, range 5 nautical miles.

1743 hours - Opened fire with the deck gun from 3500 yards while still closing the target at 12 knots.

1802 hours - The target now stopped. Again the deck gun of O 21 gave trouble.

1807 hours - Ceased fire after firing 65 rounds for only two hits. Range was now 1500 yards.

1815 hours - Boarded to place demolition charges aboard the vessel. It was thought that the crew had meanwhile left the ship. Took the ships papers from the bridge. The ship was seen to be on fire.

1830 hours - The ship was now well on fire so cast off. No need to set demolition charges. Shortly afterwards one Japanese and three natives emerged from the hold and these were taken on board.

8 Aug 1945
HrMs O 21 (Lt. F.J. Kroesen, RNN) ended her 21th war patrol (5th in the Far East, 1st of her 2nd deployment to the Far East) at Fremantle.

3 Oct 1945
HrMs O 21 (Lt. F.J. Kroesen, RNN) departed from Fremantle for Batavia, Java, Netherlands East Indies.

Media links


Onder de bloedvlag van de O21

Van Dulm, J. F.


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