Technology and Operations
This forum is for discussing technological & operational matters pertaining to U-boats.
schnorkels - pros and cons
Posted by:
kurt
()
Date: April 26, 2004 04:50PM
Ranier:
While for the Germans after the mid-point of the war schnorkels were a very good (vital) idea, they would have been of much more limited utility to allied submarine forces.
A schnorkel is primarily of use to a boat operating under heavy enemy airpower, especially if they have inferior radar or electronics to the enemy. U-boats had no, or only primitive, radar, and radar detectors that were more often than not a step behind the allies, and relatively ineffective. Under these conditions the Germans were easily be surprised on the surface without the schnorkel, and the schnorkel became vital for operational survival.
But the schnorkel came with a heavy price. Speed was severely limited to only 4 or 5 knots – extremely limiting schnorkel boat operational range during a normal patrol. This also severely limited the ability of a submarine to chase down or favorably position itself to attack enemy shipping; a slow, snorting boat had to rely on luck bringing prey to within range for an attack, since even slow merchantmen were now faster than a submerged U-boat: a submerged U-boat could not ‘chase down’ enemy shipping. Only surfaced speeds would permit that. While on schnorkel a U-boat was blind, and to a large degree deaf – unable to detect approaching enemy aircraft, or sometimes even surface ships. As allied radar improved, and schnorkels could be detected by airborne radar, much of the advantage of the schnorkel disappeared. This is shown in operational statistics: while schnorkel boats could survive better, they were only marginally more effective at sinking enemy ships in the teeth of the terrific ASW effort fielded by allied forces in the war’s later years.
In contrast, US submarines operated with less air opposition, more akin to the level faced by U-boats in the early phase of the war. Also, unlike U-boats, they not only had good, but superior radar sets, and good radar detection capabilities. A US boat, with its superior radar and electronics, could ride on the surface, knowing that it could dive before an enemy aircraft or surface ship could get close: the US boat was usually more aware of the enemy than the other way around.
This led to extended surface operations, even in areas with relatively heavy enemy patrolling. Surface operations was superior to schnorkeling because high speed was retained: US boats could track – on radar – and hunt down at 20+ knot speeds, faster than any fleeing merchantmen, and thereby attack and kill virtually anything they came across, while being able to dive to safety when warranted by radar contacts.
Given their superior radar, and the tactical situation they faced, schnorkels would have been more of a hindrance than a help to US boats.
Regards,
Kurt
While for the Germans after the mid-point of the war schnorkels were a very good (vital) idea, they would have been of much more limited utility to allied submarine forces.
A schnorkel is primarily of use to a boat operating under heavy enemy airpower, especially if they have inferior radar or electronics to the enemy. U-boats had no, or only primitive, radar, and radar detectors that were more often than not a step behind the allies, and relatively ineffective. Under these conditions the Germans were easily be surprised on the surface without the schnorkel, and the schnorkel became vital for operational survival.
But the schnorkel came with a heavy price. Speed was severely limited to only 4 or 5 knots – extremely limiting schnorkel boat operational range during a normal patrol. This also severely limited the ability of a submarine to chase down or favorably position itself to attack enemy shipping; a slow, snorting boat had to rely on luck bringing prey to within range for an attack, since even slow merchantmen were now faster than a submerged U-boat: a submerged U-boat could not ‘chase down’ enemy shipping. Only surfaced speeds would permit that. While on schnorkel a U-boat was blind, and to a large degree deaf – unable to detect approaching enemy aircraft, or sometimes even surface ships. As allied radar improved, and schnorkels could be detected by airborne radar, much of the advantage of the schnorkel disappeared. This is shown in operational statistics: while schnorkel boats could survive better, they were only marginally more effective at sinking enemy ships in the teeth of the terrific ASW effort fielded by allied forces in the war’s later years.
In contrast, US submarines operated with less air opposition, more akin to the level faced by U-boats in the early phase of the war. Also, unlike U-boats, they not only had good, but superior radar sets, and good radar detection capabilities. A US boat, with its superior radar and electronics, could ride on the surface, knowing that it could dive before an enemy aircraft or surface ship could get close: the US boat was usually more aware of the enemy than the other way around.
This led to extended surface operations, even in areas with relatively heavy enemy patrolling. Surface operations was superior to schnorkeling because high speed was retained: US boats could track – on radar – and hunt down at 20+ knot speeds, faster than any fleeing merchantmen, and thereby attack and kill virtually anything they came across, while being able to dive to safety when warranted by radar contacts.
Given their superior radar, and the tactical situation they faced, schnorkels would have been more of a hindrance than a help to US boats.
Regards,
Kurt
