PT boats and Destroyers of WWII?

[parsifal]

if you guys would join the Atlantik Pirat forums you would find probably the best of the information on the planet covering the Schnellbooten, units, personell and the Boots plus bases, etc. we are a pretty tight bunch over there and known experience is pretty intensive and high. Truly there was nothing close to these Boots in speed and agility and yes overall size was such with larger engines and arms/crew.

Ill check the site out. thanks for the heads up.

I have a few books on S-Boote operations, and unquestionably in the channel and North Sea they held a defenite advantage. However, according to my books it wasnt so much speed that gave the E Boats their advantage. They used stealth to great effect....their diesels were relatively quiet as welll. Favoured tactics involved lying in ambush fully blacked out with engines off or at very low revolutions. No wake. Engagement was aimed at minimising wakes and noise, so no Mikaels navy stuf at all really.

Successful MTB tactics were as much the reason for their success as the design. Im not attempting to claim the S Boote was not a great design...it was excellent in all its guises, but sometimes the quality of the tactics is overlooked, or not given sufficient credit.

 

[DonL]

I totaly agree with your analyse Parsifal .

What was a real advantage on their design was the very high max speed at rough seas.
The S-Boats could go 35-38kn max speed in very rough seas, where all other enemy designs must reduce their speed through the rough seas and the North Sea and the Channel have more rough sea then calm sea, so they were a very good design for this "oceans".

 

[Juha]

Yes, IMHO S-Boote were the best ones, especially S 100 class with armoured wheelhouse. Even if I have nothing against the Vospers, especially 73ft class, I also like the Dogboats and have a soft spot for SGBs, IMHO so British to built steampowered gunboats in early 40s. At least they carried respectable armament and were good seaboats.

 

[swampyankee]

The SGBs ended up being fairly useful despite their being very vulnerable to gunfire. What I found interesting is that one, SGB9(Grey Goose) of may be still afloat, as a houseboat near Hoo St Werburgh (although that datum is from wikipedia, so I'm taking it was a few grains of salt)

 

[Juha]

The SGBs ended up being fairly useful despite their being very vulnerable to gunfire. What I found interesting is that one, SGB9(Grey Goose) of may be still afloat, as a houseboat near Hoo St Werburgh (although that datum is from wikipedia, so I'm taking it was a few grains of salt)

IMHO the vulnerability was at least partly rectified when boiler and engine spaces got 18mm armour protection but that of course increased weight and so decreased max speed. IIRC some were used as blockade runners between Sweden and GB.

 

[fastmongrel]

The SGBs might not have been particulary succesful acceleration was apparently very poor and coastal boats needed acceleration more than they needed all out speed but they sure were beauties.

 

[Shortround6]

Acceleration may have changed with the armor. I wonder if they were very quite?

The Blockade runners used Diesel engines, which gave much trouble.

 

[parsifal]

This is the 1942 USN Manual for PT Boat operations. By 1942 both the USN and RN were beginning to master the tactics and skills needed to gain the upper hand in coastal warfare. With the numbers advantage they enjoyed, improvements to the craft being employed, and a cruel process of weeding out innefective crews and commanders, the two Navies were gaining control in most of the areas that they were contesting.

That is not to say the Axis, in particular the Italians and the Germans were outclassed. Its just that the qualitative gap was closing and the quantitative advantage held by the allies was becoming decisive.

In the East the Russians fielded vast numbers of Coastal craft, most of indifferent quality, but the Russians did eventually mount some effective operations. Conversely, in the black Sea in particular, the axis, led principally by the Italians (until their surrender) , with a minute application of forces were very effective at bottling up Sevastopol, and then supplying it once the Russians surrounded it again in 44.

There were any number of reasons as to why the Germans held a commanding lead in coastal operations, but they simply were unable to maintain that advantageas the war progressed.

Anyway, have a look and see what you think


MOTOR TORPEDO BOATS

The Italians (from the Regia Marina Site)

The M.A.S. in the picture below was of "500" class, 4th. series, made by 11 crafts, all constructed in 1941 by shipyard Baglietto of Varazze, Picchiotti of Limite d'Arno and Celli of Venice. Seven of those units, all lost in war, were deployed during May, 1943 in Black Sea.

At the start of war (for Italy 10th June 1940) Italy had in service 46 modern MAS of the "500" class, 25 of the 1st series (denomination from MAS 501 to MAS 525, also if MAS 506, 508, 511 and 524 were sold to Sweden at the beginning of 1940) and 25 of the second series (denomination from MAS 526 to MAS 550), other 14 similar units were under construction ("500" class 3rd series, denomination from MAS 551 to MAS 564). In that period there were in service also a little more of 15 obsolete units and some of experimental type: 5 of the class "Baglietto (SVAN) da 12 tonnellate", denomination MAS 204, MAS 206, MAS 210, MAS 213 and MAS 216; 5 of the class "SVAN velocissimo da 14 tonnellate", denomination from MAS 432 to MAS 436; 3 of the class "SVAN velocissimo da 13 tonnellate", denomination MAS 423, MAS 426 and MAS 430; 1 unit "Baglietto 1931" denomination MAS 431; 1 unit "SVAN velocissimo diesel" denomination MAS 437; 4 units "Antisommergibili Baglietto 1934" denomination from MAS 438 to MAS 441; 1 experimental unit class "500" 1st series, denomination MAS 424.

Technical data:

There were 4 sub types of the 500 series that I know of. Serie I II are fairly representative of the italian equipment

"500" class 1st series (25 units)

Shipyards: Picchiotti (shipyard's name)- Limite d'Arno (shipyard's town), Celli - Venice, S.A.C.I.N. - Venice, C.R.D.A. - Monfalcone.

Commissioned: 1937, uncommissioned from 1940 to 1951 (11 lost or captured in war actions)

Dimensions: Length 17.0 m Width 4.4 m Draught 1.25 m

Full load Displacement: 22 ton

Speed max.: 44.0 knots

Autonomy: 400 miles at 42 knots, 1000 miles at 6 knots

Armament: 1 - 13.2 mm. machine gun, 2 - 450 mm. torpedoes (2 launchers), 6 depth charges (1 launcher).

Crew: 9

"500" class 2nd series (25 units)

Shipyards: Picchiotti - Limite d'Arno, Celli - Venice, C.R.D.A. - Monfalcone, Baglietto - Varazze.

Commissioned: 1939, uncommissioned from 1940 to 1950 (16 lost or captured in war actions)

Dimensions: Length 18.7 m Width 4.7 m (exception MAS 550: 4.6 m) Draught 1.43 m (exception MAS 550: 1.3 m)

Full load Displacement: 25.5 ton (exception: MAS 550 was 21.0 ton because it had metallic hull instead of wooden)

Speed max.: 44.0 knots (45 for MAS 550)

Autonomy: 400 miles at 34 knots, 1100 miles at 6 knots (MAS 550: 400 miles at 45 knots and 1100 at 6 knots)

Armament: 1 - 13.2 mm. machine gun, 2 - 450 mm. torpedoes (2 launchers), 6 depth charges (1 launcher).

Crew: 10

 

[parsifal]

Soviet MTBs were generally small, and utilised stern launching systems, which eliminated the use of stealth, and made torpedo aiming difficult. This in practice generally meant Soviet torpedo attacks were inneffective.

On the other had, the small size of the Soviet MGBs made them ideal river assault craft, and there are quite a few instances of Soviet river flotillas having a significant impact on particular campaigns, including several of the major ones.

Soviet torpedo boats were developed from experience with their own Type Sch4 (an earlier Russian design–itself based on British First World War CMBs), Italian plans, and new Soviet design ideas. The majority of all Soviet high-speed motor torpedo boats of World War II were of this type, called G-5.' Its specifications were:
Length: 19 meters (roughly 60 feet)
Beam: 3.3 meters (about 17 feet)
Draft: 1.5 meters (almost 5 feet)
Displacement: 14.84 tons
Speed: 48 knots loaded, 53 knots stripped
Machinery: Two 850 hp. GAM gasoline engines
Armament: 1 12.7mm (.50 cal) machine gun, 2 53.3 (21 inch) torpedoes in stern troughs


Interesting features of Type G-5 were the light aluminium hulls and the change to the more powerful 21 inch torpedo (earlier Soviet attempts to develop MTBs used the 18 inch torpedo). Type G-5 was built from 1930 to 1939 to various specifications as Series 7, 8, 9,10, and 11, with the last named series being produced in 1939, fitted with two GAM 34 BSF engines which called for more robust hulls, and one boat was reportedly able to attain a speed of 62 knots unladen.'

Some 329 boats were built to this design from 1934-1944, divided into five basic series. In 1942, following the successful use of home-made Katyusha 88mm rocket-launchers from boats of this type, the naval authorities ordered 82mm and 132mm army rocket-launchers to be adapted for naval use (242 had been ordered by 1945). Some of the G5-class boats completed from 1943 to 1944 had torpedo wells plated out, and missile-launchers mounted above the conning tower.

Since the mid-1930s the Soviet Navy had run an experimental programme with a view to producing large, seaworthy motor torpedo-boats. Following trials of the G5- derived boats of various sizes, the stern-launching system was abandoned in favour of deck torpedo-launching racks. Soon two types of wooden- and steel-hulled boats of this kind were selected for further evaluation. The general performance of the larger, wooden-hulled boat was found to be satisfactory and series production began in 1939 under the designation D3 class. Because of engine shortages fifty-six hulls were completed as subchasers and it was only when Packard engines became available that the construction programme reached its peak. A total of 119 boats, (torpedo-boats or subchasers) had been built by 1944.
Displacement 32.1 tonnes full load
Dimensions 21.6m overall length x 3.9m beam x 1.35m max draught
Armament two 533mm torpedo tubes/launching gears, two 12.7mm MG. eight depth-charges
Electronics Tsefej-type hydrophones
Machinery 3-sbaft GAM-34F petrol engines, 3,150bhp
Speed 37kts
Endurance 550nm at 8kts
Complement 2 officers and 6 – 8 men

Soviet Warship Building and Actions
The Soviets built a large number of MTBs during the war and were definitely able to replace them. Between 1941 and 1945 Soviets built (at least):
31 – Komsomolets class
5 – Yunga class
38 – D-3 class
71 – G-5 class
1 – STK DD class

Of all the coastal fleets of the war, that of the Soviet Union perhaps had the strangest collection of craft. Starting in the mid 1930s, Russia built scores of small, very fast aluminum G-5 MTBs . Based on the old CMBs with stern launching torpedoes, these boats attacked en mass, usually lost a boat or two in the process, and seldom hit anything. Stern launched torpedoes demanded high speed attacks, so the stealth tactics developed by other navies were not an option.Their aluminum hulls, the design of which was based on float-plane pontoons, deteriorated in the salt water and they had to be moored up river or taken out of the salt water. Many mounted 82mm rocket launchers, these being used more for support of ground troops than against shipping. Many were actually lost in collisions and several were captured by Axis forces in the Black sea and Gulf of Finland. Larger wooden hull D-3 boats were also made along with various steel hull prototypes. One of these, the SM-3, sank several Axis vessels in the Black Sea including an Italian sub! The Russians also had many lend-lease PT and Vospers. While their MTBs were unspectacular, the Soviet Navy developed small armored gunboats to a science. The 1124 and 1125 classes were heavily armored and had tank turrets mounted on the hull. Some mounted "Katyuska" multiple rocket launchers. These river tanks as they were called only drew 2 of water and were also used as landing craft for naval commandos.

Coastal warfare in the Black Sea and the Baltic has not received much attention. Italian MAS boats sank a Soviet Cruiser in the Black Sea. Along the Crimean coast, battles between Axis MFPs, S-boats and R-boats against Soviet MTBs and motor launches approached ferocity seldom seen in other waters. Finland used a handful of obsolete boats initially with telling effect on Soviet shipping. As the war went on, Italian MAS boats and some captured Russian vessels were added to the Finnish Navy inventory. Action was seen on both Lake Ladoga and the Baltic, with mines being the weapon of choice by both sides. By 1944, the Gulf of Finland was the most densely mined body of water in the world.


Jurg Meister credits the MTBs with sinking 1 Finnish minesweeper, 4 German minesweepers, 1 German torpedo boat, approximately six small German auxiliary minesweepers or patrol craft, and approximately four large and 10 very small German merchant ships, fishing boats, or other small craft, plus two Japanese merchant ships.

In WWII following ships were sunk by Russian surface warships:
Transport "Tania" – Jan, 20 1943 by DL "Baku"
Submarine "U-585″ – March, 30 1942 by DD "Gremyaschiy"
Submarine "U-286″ – Apr, 22 1945 by DD "Karl Liebkhnecht"
Submarine "U-334″ – Aug, 22 1944 by DD "Derzkii"
Submarine "U-387″ – Dec, 9 1944 by DD "Zhivuchii"
Submarine "U-2342″ – Dec, 26 1944 by sub chaser "MO-113″
Submarine "U-679″ – Jan, 9 1945 by sub chaser "MO-113″
MTB "Rau" – May, 5 1943 by sub chaser "MO-114″
Submarine "U-250″ – July, 30 1944 by sub chaser "MO-313″
Submarine "U-362″ – Sept, 5 1944 by minesweeper "T-116″

While obviously not a stellar success, they did sink some ships. MTBs and submarines were somewhat more successful.

 

[Juha]

Acceleration may have changed with the armor. I wonder if they were very quite?

The Blockade runners used Diesel engines, which gave much trouble.

SGB were fairly quiet, one of their good points. The main problem was their high fuel consumption. As steam powered vessels they had to keep steam pressure up all time while in patrol, so that they could react untowards surprises in reasonable time. Those boats with combustion engines could wait with engines idling or even stopped ans simply open the throttles when needed.

 

[DonL]

I think the largest and most advanced advantage of the S-Boats, next to the Lürssen effect and their high speed at rough seas, were the engines of the S-Boats.

The MB 501/518 diesel engines were developed out of the Luftschiffmotors LOF 6/DB 602 engine of the Zeppelin Hindenburg beginning of the 1930 years and were action ready 1935. This engine class was State of the Art till 1965 and was the cutting edge over 30 years. The last german S-Boat class with this original further developed MB 518 engine was the Zobel class from 1962/63 which were in service till 1983/84.


I think this engine is one of the main reasons of the success of the S-Boats.
Also this engine was exported in over 35 countrys after the war and even the USA bought this engine.

 

[fastmongrel]

There was a British diesel engine called the Berdmore Tornado designed for airships that could have been developed for coastal boat use but it never got the time or money to make it succesful.

Beardmore Tornado - Wikipedia, the free encyclopedia

Napiers licensed the Junkers Diesel engines pre war, another missed opportunity to get a powerful marine diesel for British coastal forces

Napier Culverin - Wikipedia, the free encyclopedia

Diesel engines of the power needed do seem to have been one area where Britain dropped the ball inter war.

 

[DonL]

I think that the MB 501/518 was the first realy modern V-Diesel four stroke high performance engine and was clearly superior to all normal diesel inline engines, for high performance power output.

Daimler-Benz DB 602 - Wikipedia, the free encyclopedia
Schnellboot ENGINES
Mercedes-Benz MB 518

2000 PS out of 4000kg was a very good power to weight ratio for Diesel powered engine.
Later the MB 518 reached 3000 PS out of 5000 kg and 3500PS out of 5500kg.

 

[swampyankee]

I think the only area where WW2-era German technological superiority cannot be disputed is diesel engines, especially high speed marine diesels. I think it's also because the German Navy's leadership felt that this sort of coastal craft was very important: neither the USN nor RN thought this, so their coastal craft were not subject to anything like the R&D that went into the S-boats.

Could the UK or the US have developed the type of high-speed diesels and round chine hulls used by the S-boats? Sure; the latter was known: the hard chine hullform used for the RN's and USN's MTB/MGB/PT boats was a conscious decision, not one of ignorance (hard chine boats are easier to construct, and have better high speed performance in many sea states), and the former was certainly possible: UK and US makers had made aircraft diesels of domestic design, but neither navy gave much thought to coastal vessels, due to their strategic visions.

 

[DonL]

I have seriously my doubts, that such an engine could be developed out of the blue and have not seen till now, any equal allied high speed (rpm) diesel engine from this timeline (WWII).
More important a diesel engine with this power to weight ratio and compactness.

 

[swampyankee]

I have seriously my doubts, that such an engine could be developed out of the blue and have not seen till now, any equal allied high speed (rpm) diesel engine from this timeline (WWII).
More important a diesel engine with this power to weight ratio and compactness.

The development of the diesels used in the S-boats started no later than the late 1920s, with the DB-502 installed on the S10 through S13 in 1933. The USN and RN had absolutely no reason to develop engines of similar performance before about 1940, and even at that time, the services had higher priorities: the RN needed ASW vessels and the USN needed long-ranged ships. Guiberson and Packard made production aircraft diesels in the US; Beardmore did so (less successfully) in the UK.

I'm not claiming that US or UK makers could have whipped up DB-501 like engine in a few weeks; I'm claiming they could have had such engines in service in 1940 had they been willing to start spending the money sufficiently far in advance, which would be no later than about 1936 or 1937.

 

[parsifal]

I think this engine is one of the main reasons of the success of the S-Boats

.


Agree completely, and it was a major handicap for the allies to overcome. however this was not the only technological advantage they possessed. The hull form was a modified chine that really assisted in wakeless approaches and also, as youve mentioned earlier, this hull form gave the S-Bootes the ability to handle rougher weather at higher speeds

The Royal Navy efforts started from a long way behind both Italy and Germany. The RN viewed MTBs with a great deal of disdain, and in the interwar period had resolutely resisted any significant research into the field. Britain consequently entered the war with completely unsatisfactory equipment. They never fully closed the gap, but they reduced the margins of difference over time, such that by 1942 tey were making serious challenges to German control of the Channel.

The "father" of the RN Coastal forces is undoubtedly Lcdr Robert Hichens. on the very day he graduated as a law student he drove to Falmouth toenquire about the RN reserves. he was dismayed to learn that he, and any other 'inlanders" would have to travel twice weekly to Falmouth for training, and managed to persuade the RN to form the RN supplementary reserves, which concentrated on raising training chapters in the inland areas of England, far fom the Coast. It was from these chapters that most of the good small boat commanders were drawn.

Hichens dominated the RN Coastal Forces development until 1943, when he was finally killed. His story is a great guide on the RNs gradual development of its light forces. he led many raids personally and there is a measurable increase in the success rate for the RN as they developed the skills the experience and the equipment needed to gain the upper hand in the shallow seas around Britain 1941-3. Hichens received the DSO twice, both with bars, and was also mentioned in dispatches either twice or three times. He was killed in dramatic circumstances in 1943.

Britain had a successful CMB and Toredo Boat fleet in the first world war, but had almost completely demobilised it by 1919. From there until 1937 there was virtually no interest. The first post war design was a 60 foot Vosper, so-called series I "short MTB". These designs were of a 60 foot hard chine Hull section. It was built by the British Power Boat Company design, driven by a 500 HP Napier petrol engine. The design was a start, but anything but stellar. It had a top speed of 33 knots, 2 x 18 in torps and defensive armament of 2 x 7.7mm LMGs (this was modified as the war progressed, but the design was too limited to allow much to change) . These designs had a lasting infuence on British MTB design. Six Boats were purchased and placed under the command of Lcdr GB Sayer organized as the 1st MTB Flotilla. They were deployed at Malta from 1937 onward. Unlike the germans, who were already building light metal framed round bilged hulls, British hulls were still using plywood framing and hard chine profiles.

By comparison, the German S-1, built in 1930, was 90 feet long, and powered by 3 x 1000hp MAN diesels. it was hard chined, but carried heavy 21 in torps and a single MG. They were shown to be not well suited to rough seas, so a modified and enlarged design was developed, 106 feet long, round bilge hull form, metal framing, enclosed cockpit area, 1320 HP diesels, gun armamanet increased to a 20mm calibre with explosive shells. 8 of this class were builot in 1934. This design was further improved in the next series. Lengthened to 114 feet, with more powerful diesels (which gave over 6150 BHP combined), with sustained max speed of over 40 knots. 19 had been built by 1939.

Germany scrapped her series 1 boats and went to war with 24 very modern and capable series II and series III boats. 5 boats were already considered obsolete, and Lurssen had yet another improved model under construction in 1939. S-26 came into service from 1940, and over 100 entered service over the next three years. they were very dangerous and effective ships. They had a 4 x 21 in broadside, with forward tubes enclosed. Most retained their twin 20mm cannon, but a few were upgunned with a single 40mm cannon.

In Britain development was at least 5 years behind the Germans. in 1937, a further 12 Type Is were built, 6 were shipped to Hong Kong. The other 6 were intended for Singapore, but in 1939 were firstly diverted to Egypt and then were added to the 1st Flotilla at Malta

The admiralty was at last beginning to realize the potential of coastal craft. Two boats were built as improved type 1s as a private venture. One of these prototypes was used as the basis of the RNs next "short MTB" design, of which the Type II Vosper type was typical...72 feet long, hard chine planing hull, petrol engines, 4040 HP, top speed of 40 knots+. 2 x 21 in torps (external mounts) 2 x 12.7mm HMG and 2 x 7.7mm LMG. Over 200 of this basic design were built, and it was these, and similar, that bore the brunt of the early fighting 1940-42. There were progressive improvements and increases in armament of these basic types, and in an effort to reduce losses, the short MTB design branched into two main subtypes, the MGB, which emphasises gun armament, and the true torpedo carrier. A big improvement began to appear with super silenced engines and upgrades in armement. But there were no suitable diesel powereplants and this remained a big problem.

It was the short boats that did most of the heavy lifting, though the Fairmile D (the Dogboats) had over 200 built. The Dogboats were effective, but too slow to be used in a really offensive role

 

[DonL]

Thank you for this very good informations.

 

[Juha]

I think the largest and most advanced advantage of the S-Boats, next to the Lürssen effect and their high speed at rough seas, were the engines of the S-Boats.

The MB 501/518 diesel engines were developed out of the Luftschiffmotors LOF 6/DB 602 engine of the Zeppelin Hindenburg beginning of the 1930 years and were action ready 1935. This engine class was State of the Art till 1965 and was the cutting edge over 30 years. The last german S-Boat class with this original further developed MB 518 engine was the Zobel class from 1962/63 which were in service till 1983/84.


I think this engine is one of the main reasons of the success of the S-Boats.
Also this engine was exported in over 35 countrys after the war and even the USA bought this engine.

One of the most memorable moments in my life is the moment when I stepped in the reconstruction of S-Boot engine room at Deutsches Museum in the summer 75. The 3 diesels and the audio system, vau!

Juha

 

[Vassili Zaitzev]

They weren't the best...by a long shot. Still, the Clemson-class destroyers of the US Asiatic Fleet gave a good account against the Japanese Navy. Here are some the 'Four-Pipers' of Destroyer Squadron 29.