LMS Jubilees

The LMS Jubilees

The LMS Jubilees were a type of 4-6-0 express passenger locomotive designed by William Stanier after he became Chief Mechanical Engineer (CME) of the London Midland and Scottish Railway (LMS). In 1932 William Stanier arrived from the Great Western Railway (GWR) and his task was to produce a modern range of standard locomotives to replace many indifferent and varied pre-group designs. The Jubilees were a second-line 4-6-0 power-classified 5XP as were the Claughton class and the Patriot class.
Back in 1927 the LMS had solved the problem of first-line motive power with the development of the Royal Scot class a 3-cylinder 4-6-0 design. After the loan of GWR 4-6-0 No. 5000 Launceston Castle in 1926 to work the ex-LNWR main line for trial purposes had been a success, the LMS authorities decided that a 4-6-0 wheel arrangement would be sufficient. Ideas of developing a new compound 4-6-2 or double-heading 4-4-0s were dropped. With the aid of Southern Railway ‘Lord Nelson’ drawings and the efforts of the North British Locomotive Company the ‘Royal Scot’ was born. The North British Locomotive Company delivered 50 locomotives in good time and Derby Works built another 20 in 1930. As first-line 4-6-0s they displaced the Hughes 4-6-0s and some of the Claughtons.
The Claughton class 4-6-0s were a 1912/13 design from the old London & North Western Railway by Bowen-Cooke with 4 cylinders. The Claughtons were good locomotives and on introduction an improvement over existing LNWR express passenger classes. However the Claughtons were inferior to the GWR 4-6-0s then in service. An outstanding feature of the GWR 4-6-0s was the taper boiler which would be used extensively by William Stanier for his designs including the Jubilees. After 1927 as second-line locomotives the Claughtons were in need of improvement as despite many modifications repair bills were heavy. Twenty locomotives were re-boilered but even then all was not well.
There was a need for a new type of 4-6-0 lighter than the ‘Royal Scots’ and able to operate on restricted routes. The approach was to pair the new ‘Claughton’ boiler design with the ‘Royal Scot’ chassis. Some ‘Claughton’ components were utilised for the first two locomotives and although they were practically new locomotives the LMS considered them to be ‘Claughton’ rebuilds for accountancy purposes. The locomotives were unofficially called ‘Baby Scots’ but became the ‘Patriot’ class when the name ‘Patriot’ was transferred from the ‘Claughton’ LNWR war memorial locomotive to one of the new engines. The ‘Patriots’ proved to be superior on test to the rebuilt ‘Claughtons’ and also cheaper to maintain.
When William Stanier arrived from the GWR to take up his post as CME he was content to allow some current production to continue and a batch of forty ‘Patriots’ was built followed by a further ten in 1934. The ten ‘Patriots’ were part of an order for fifteen 4-6-0s the last five being earmarked to receive taper boilers of type 3A together with improvements to all fifteen in the way of wheels, tyres, bogies and axleboxes. The 3A taper boiler, design of which had commenced in June 1932, combined with the 3-cylinder ‘Patriot’ chassis defined the basic form of the new ‘Jubilee class. The first taper-boilered locomotive No.5552 was exhibited at Euston station on 23 April 1934 and was soon followed into service by the remainder of the batch Nos.5553-6. The new locomotives were finished in LMS standard passenger livery of crimson lake, lined in yellow and edged in black. The cab differed from that of the ‘Patriots’ in having two windows on each side, instead of a window and cut-out. Many Stanier improvements had not been designed in time to be incorporated in the early examples. Some bogies used were modified ex-‘Claughton’ units, made available from withdrawn members of that class.
The first 53 locomotives were built at Crewe Nos.5552-6 and 5607-54 together with 10 at Derby Nos.5655-64. The gap of 50 running numbers (5557-5606) was to be filled by an order placed with the North British Locomotive Company in October 1933 to be delivered in the summer of 1934. All three orders were executed in 1934/5 the last NBL locomotives going into service during February 1935. The orders were placed straight from the drawing board and as such there was an element of risk involved.
All the new 4-6-0s were in traffic by April 1935, a total of 113 by that date. Early examples were put to work on the Euston to Birmingham services and unfortunately proved inferior to the ‘Patriots’ they were intended to replace. The main reason was an impaired steam-producing capacity. The boilers based on Swindon practice and thinking did not prove entirely suitable for LMS conditions with a three-cylinder locomotive. The calorific value of the coal used was less than that of the best Welsh steam coal used on the Great Western. During tests it was found that the smokebox retained excessive ash deposits each day indicating that all was not well and focussing attention on the draughting. Modifications to increase the superheating level were put in hand on 4-6-0s then being built at Crewe and in December 1934 Nos.5642 to 5646 were completed, with modified tubeplates and a 21-element superheater. As soon as possible No.5642 was inserted into the Wolverhampton to Euston service for a one day dynamometer trial. Steaming was still not adequate, although the fuel and water consumption had improved.
Tests resumed in February 1935 using locomotives 5646 and 5556 with modified blastpipe and superheating arrangements. Results of the trials were encouraging but not entirely so. Further tests in April compared three ‘Jubilees’ with two ‘Patriot’ 4-6-0s and still the taper-boiler 4-6-0s were not reaching full expectations. The operating department did not place any great reliance on the new locomotives for the accelerations of the Euston and Birmingham services due in the winter 1935 timetable. As a result most of the Midland Division ‘Patriots’ were transferred to the Western Division in exchange for the taper-boiler 4-6-0s.
In 1935 to commemorate the Silver Jubilee of King George V the LMS decided to name one of the 4-6-0s Silver Jubilee and in April selected one of the newest locomotives for this honour. No. 5642 was repainted a very high gloss unlined black, with chrome plated boiler bands, cab window beading, handrails and domecover. It was also given chrome-plated raised numerals and letters of block pattern, in similar style to that which was introduced in transfer form generally in 1936. No. 5552 and 5642 exchanged identities so that No. 5642 became the official first member of the class. Silver Jubilee went on a publicity tour of the LMS system in 1935. The locomotive also gave its name to the class as a whole, although the title was soon abbreviated to the ‘Jubilees’.
The final orders for ‘Jubilees’ were placed on Crewe, thirty (5665-5694) in June 1934 followed by forty-eight (5695-5742) in July 1935. These were the last orders bringing the class total to 191.
The ‘Jubilee’ problems continued to receive attention, there were several boiler variations in existence and each was being tested, events were now reaching well into 1935. Modifications were applied to new locomotives as they were being built. From 5665 onwards (new in November 1935) the locomotives received redesigned boilers with larger superheaters, a larger grate area, sloping throatplate, smaller tubes, separate dome and top feed, and reduced blastpipe diameter(from 5 1/8in to 4 7/8in). Tests recommenced in February 1936 with the dynamometer car on the Euston to Wolverhampton route, and continued for nearly a month, using locomotives 5665, 5669 and 5684. No.5665 was the best and the one which pointed the way ahead to success. The solution was clearer by May 1936 when No.5702 went into traffic fitted with the 15th boiler variation, having 24-element superheating and l 7/8 in diameter tubes. With much effort, overseen by Stanier’s Chief Draughtsman Tom Coleman, the problems were mainly overcome. Tests continued during 1937 and results on the former Midland lines south of Leicester were encouraging. No.5614 was tested between St.Pancras and Leeds with good results. During October No.5660 Rooke was tested for four days between Bristol and Carlisle (via Leeds and Ais Gill) and produced some remarkable performances. The schedules involved a very high power development from No.5660 and consequently a high combustion rate. It was felt that the rate of working was ‘beyond that which could be recommended in all circumstances for daily operation’. Perhaps the most impressive feat was the climb of 1,150 ft in 48.4 miles from Carlisle to Ais Gill summit, achieved in 48.5 minutes. Perhaps any lingering doubts that remained were that this ‘standard’ class now had so many variations which could influence performance.
The ‘Jubilees’ were a named class of locomotive but it took a while for the LMS to decide on a naming policy. In 1936 the LMS released its list of selected names. The themes were British colonies, Commonwealth countries, dependencies, states, provinces, admirals of the Royal Navy, famous sea battles, and warship names.
Towards the end of 1939 the class had settled down to everyday usage. They were well dispersed on the LMS system including Scotland and the Midland Division where, ‘Patriots’ excepted, they were the best passenger locomotives to appear since the compounds.
During the war the Jubilees were to tackle slower but heavier trains, with reduced maintenance, poor coal, and unkempt appearance due to shortage of manpower for cleaning. The frequent starting of semi-fast trains was within the adhesive capability of the ‘Jubilees’ but their power to do it quickly, with loads approaching half as much again as in peacetime, was insufficient. In addition to passenger and mixed traffic duties the ‘Jubilees’ were also employed on heavy freight work.
During the war two ‘Jubilees’ were rebuilt with larger taper boilers – Nos.5735 Comet and 5736 Phoenix. The new boiler started development with No.6170 British Legion which was a ‘Royal Scot’ chassis with the taper boiler, designated No.2. British Legion was created by rebuilding the experimental 4-6-0 No.6399 Fury a failed high pressure steam design. The boiler No.2 fitted in 1935 suffered from indifferent performance but design work on a development the 2A started in 1939. The boiler 2A fitted to Comet and Phoenix retained the firebox design but had a new shorter barrel with 13 feet between tube-plates. There were twenty-eight superheater elements and 198 small tubes 1 ¾ in diameter. The smokebox was fitted with a plain double blastpipe and chimney. Comet and Phoenix went into surface in April and May 1943, used on the Leeds to Glasgow and Leeds to Bristol services. The 2A boiler was eventually used to re-boiler all 70 parallel boiler ‘Royal Scots’ and 18 parallel boiler patriots, the ‘Royal Scot’ conversions not being completed until 1955. More ‘Jubilees’ could have been converted but a drawback to the idea was that the ‘Jubilees’ had comparatively new taper boilers.
The post-war LMS period only lasted 2 ½ years. The railway had to accept a continuation of some wartime restrictions during a period of austerity and shortages. Much maintenance needed to be done particularly of the permanent way. Many express trains did not achieve pre-war timings until 1954.
After some experiments it was decided that black would be the basic livery for all classes and that lining would be applied to passenger locomotives only. The lining was a straw shade with maroon being used for edging and between two straw lines along the valances. A few ‘Jubilees’ received this 1946 livery, the nameplates were maroon with lettering and surround picked out in straw.
The LMS ceased to exist on 31st December 1947 after which it formed the nucleus of the London Midland Region of British Railways, with lines north of the border becoming part of the Scottish Region. After a number of experiments in BR days the final livery for the ‘Jubilees’ was the passenger livery of Brunswick green similar to that used by the GWR for many years. Around 1950 smoke deflectors were fitted to the rebuilt ‘Jubilees’ Comet and Phoenix, the same small curved type used for the rebuilt ‘Royal Scots’ and ‘Patriots’. The following year the rebuilt locomotives were all reclassified 7P while the unrebuilt ‘Jubilees’ were reclassified from 5XP to6P.
The first ‘Jubilee’ to be lost from service was No.45637 Windward Islands which was damaged beyond repair in the Harrow and Wealdstone disaster on 8th October 1952. The locomotive was so badly damaged that she had to be cut up on the spot and transported to Crewe works in manageable sections. The final death toll from the multiple collision was 108 passengers and four locomotive crew.
In 1957 passenger services were accelerated on the Midland main line and the ‘Jubilees’ bore the brunt of these as the largest passenger locomotives on the line. Inferior fuel and maintenance left much to be desired in the performances and pilot locomotives were often needed. The official answer was to bring in ‘Royal Scots’ and later ‘Britannia’ class locomotives and the better examples of these eliminated much of the piloting.
The next ‘Jubilee’ to be withdrawn was no.45609 in 1960. Dieselisation affected the ‘Jubilees’ from an early date and they were put onto a mixture of secondary workings. Occasionally they were picked out to replace failed diesels on express passenger workings. The number of withdrawals peaked in 1964 at 66 engines and in 1965 a further 33 were withdrawn leaving 15 examples in service. After the last general overhauls in 1965 the last examples were outshopped in unlined green. Survivors during the early 1960s were given a diagonal stripe across the cabside indicating that they were not allowed beneath the 25 KV electrified sections of the West Coast route. The final three were withdrawn in 1967 the last officially being no.45562 Alberta.
Three examples of the ‘Jubilees’ were bought privately for preservation and a fourth purchased as a source of spare parts for one of them. The preserved locomotives are no.45593 Kolhapur, no.45596 Bahamas, no.45690 Leander and no.45699 Galatea to act as a source of spare parts for Leander.

The Electro-boat: Type XXI U-Boat

The idea for the Type XXI arose at a conference in November 1942 at Admiral Doenitz’s Paris headquarters. The conference was attended by Professor Walter and the technical experts Schuerer, Broeking and Waas. The Walter boats were discussed as a way of producing submarines with a much greater submerged speed. The V80 a 4 man 76-ton prototype submarine completed in 1940 reached a submerged speed of 28 knots. A problem was the very large amounts of hydrogen peroxide required compared to diesel consumption for example. Helmuth Walter had designed the type XVIII boat with a figure of 8 hull cross section, the lower hull to be used to store hydrogen peroxide. Once the hydrogen peroxide had been consumed within a few hours the submarine would have to revert to an inferior conventional propulsion system. Doenitz learnt to his regret that the Walter U-boat was nowhere near ready for service. He could not accept the responsibility of recommending that the Walter U-boat should be put at once into mass production.
The engineers Schuerer and Broeking suggested taking the basic type XVIII design and using the lower hull to store batteries instead of hydrogen peroxide. The result would be to triple the submarines battery capacity but with a conventional diesel electric system. The possibility existed of a much enhanced underwater performance with a shorter development time than would be required for the Walther submarine. Doenitz, head of the U-boat arm and soon to be head of the Kriegsmarine, agreed to go ahead with the electro-boat idea. Another advantage of using the type XVIII hull design was that hydrodynamic testing had already been carried out. Professor Walter suggested the development of an air intake and expulsion apparatus, later called the snorkel, which would avoid the necessity for the submarine to surface to recharge its batteries.
In June 1943 some time after he had become Commander-in-Chief Doenitz was able to examine the blue prints of the new design. As the Type XXI design developed a number of significant improvements were made compared to the previous Types VII and IX. For the first time in a diesel electric design more power was to be developed under water than on the surface, 5000 hp versus 4000 hp. Low power creeping electric motors were developed which would allow very stealthy under water running at speeds up to 6 knots. In general the Type XXI was much more streamlined than previous U-boats with as few external protuberances as possible. There was no main gun but two anti-aircraft turrets blended in to the fore and aft parts of the conning tower. Each turret had a pair of 20 mm anti-aircraft cannon. The Type XXI had six bow torpedo tubes and no stern tubes, and was able to carry 23 torpedoes altogether. An improved torpedo reloading system allowed 3 salvoes of 6 torpedoes to be fired in 20 minutes. The submarine had a figure of eight cross section for the pressure hull and a streamlined outer hull parts of which were free flooding. The number of free flooding holes had an effect on the water resistance, and hence maximum speed, and the diving time. The best compromise resulted in a maximum submerged speed of 16.8 knots and a diving time of 25 seconds. Because the pressure hull was not circular it was more difficult to calculate the safe diving depth. In deep diving tests depths of more than 200 metres were reached. The boat had two 6 cylinder diesels developing about 2000 hp each when used with superchargers. The two electric motors developed 2500 hp each for the maximum submerged speed and a slightly higher speed on the surface showing that the hull was also well designed for surface running. Unfortunately the superchargers did not work well particularly when snorkelling and were deleted from many of the submarines. As a result the maximum speed on the surface under diesel power was reduced from 15.6 knots down to about 14 knots. The maximum snorkelling speed was only about 6 knots due to oscillation problems with the snorkel which was an extending type and not as strong as other designs. The facilities for the crew were better than in the previous Type VII and IX designs. There was improved air purification and regeneration apparatus, a freezer for better food storage and a washroom with three wash basins and a shower.
In the early stages of the Type XXI design it was expected that two prototypes would be built and thoroughly tested before embarking on mass production but that would probably mean that the submarine would not become fully operational until 1946. With the U-boat war having reached a critical stage Doenitz realised that something would have to be done to speed up the normal production process for a new type of submarine. Doenitz consulted with Albert Speer the armaments minister and he brought in Otto Merker an industrialist with experience of mass production in the automobile industry. A plan was devised to produce the Type XXI straight from the drawing board with a wooden mock up but no actual prototype. In a complete departure from normal submarine construction at that time, the submarine was divided longitudinally into 8 sections which were completed separately and only brought together in the final assembly stage.
The first stage in the construction was the basic steel building stage carried out at many steelworks throughout Germany. At this stage the pressure hull, outer hull, bulkheads, decks and tanks were constructed. Many of the steelworks involved had no previous shipbuilding experience. The basic steel modules were then transported by inland waterways to the section outfitting stage. At this stage yards with experience of submarine construction would complete the sections to a high state of readiness. Finally the sections or modules were transported to the final assembly yards with access to a river or the sea for the launching. The sections would be arranged on the slipways and then carefully lined up for the welding stage. Four welders would weld two sections together over a period of about 8 hours with no stoppages allowed either for weather or air raids. There were three final assembly yards Blohm & Voss, Hamburg; Deschimag Weser AG, Bremen and Schichau, Danzig.
The modular construction system allowed the U-boats to be constructed more quickly but many of them were completed with a number of faults and had to keep returning to the shipyards as a result. The de-centralised construction of sections gave some protection against air raids but the assembly yards were still vulnerable. Late in the war the assembly yards were heavily bombed which slowed construction. Ideally the final assembly stage would have taken place in reinforced concrete bunkers but they were not ready in time. A lot of pressure was put on the shipyards to produce a large number of U-boats but it worsened some of the problems. For example some sections were sent forward with parts missing in order to keep to the scheduled date. Some of the early boats were constructed without a snorkel and had to return to the yards to have them fitted causing more delays. The hydraulic system originally intended for the type XVIII boats turned out to be over complicated and had to be redesigned. Another problem when the U-boats were tested was that the turning circle was too large but it was too late to change the single rudder design. Additionally the diesel and electric motors were not separated by a clutch, because it was assumed that the large battery installation would always need charging. As a result some electric motors running in reverse caused water to be sucked into the diesel engines.
However despite all the faults the Type XXI was probably the right concept as a U-boat to take over from the Type VII and Type IX designs. Although considerably larger than the Type VII the Type XXI could still dive fairly rapidly. The Type XXI could carry 23 torpedoes compared to 14 for the Type VII and with 6 tubes at the bow and a rapid reloading system could fire many more torpedoes in a short time. Also the Type XXI could carry more fuel and provisions, enough for a long voyage in the Atlantic without needing to be resupplied.
The most revolutionary aspect of the Type XXI was its underwater speed and endurance. The speed of over 16 knots would give it a much better chance of penetrating an escort screen and getting into a good firing position to sink a number of merchant ships. The high speed would also give it a much better chance of escape from the escorts following an attack. Also using the creeping electric motors a stealthy disengagement was possible at 6 knots for up to 48 hours.
The poor underwater performance of the Type VII meant that it was very difficult to get into a firing position even with a convoy travelling at only 10 knots. In the early part of the war type VII boats attacked on the surface at night but that was becoming increasingly difficult by the time the Type XXI was being considered. Also hunter-killer groups when able to hunt a U-boat away from a convoy could take advantage of the poor underwater performance to stay with a U-boat, such as the Type VII or Type IX, until it was forced to surface.
Normally accepting a new U-boat into the Kriegsmarine involved the crew in ‘standing-by’ the U-boat as it neared completion and then taking it over on the commissioning day. The crew was then involved in testing the U-boat along with the construction yard. When all was satisfactory the boat was taken for a shake-down cruise in the Baltic with a training flotilla and the crew was trained in the latest operational techniques. Because so much of the equipment was new the whole process took much longer with the Type XXI compared to the Type VIIs and Type IXs. Type XXI crews made desperate efforts to prepare their boats for operations before the war ended. However many completed boats needed modifications or repairs which could not be done in time.
A number of boats left German ports heading for the U-boat bases in Norway but only two commenced war patrols before the war ended. On April 30 1945 U-2511 put to sea from Bergen, Norway, with orders to go to the Caribbean. The boat was detected by an anti-submarine patrol group off the Scottish coast but easily escaped. On May 3, after receiving the surrender order by radio, the commanding officer, Schnee, had the British cruiser HMS Suffolk in his sights at a range of 600 metres and went through the motions of an attack, braking off at the last minute. He dived under the target and returned to Norway without being detected. The other war patrol was commenced by U-3008 which sailed from Wilhelmshaven just before the surrender. U-3008 carried out an undetected dummy attack on a British convoy before returning to port.
Although the Type XXI was a revolutionary design the programme as a whole was a failure because the type did not become operational in sufficient numbers before the war ended. Despite using the sectional construction system not enough boats reached a stage of operational reliability and there was no possibility of making an impact on the Battle of the Atlantic. Statistically 120 boats were delivered but most were constantly having to return to the yards for repair or modification or were still training and not ready for combat. Unfortunately all the cutting of corners and the pressure to produce the U-boat in large numbers lead to mistakes in detail design which added to the problems.

Specifications

Displacement

Surfaced: 1621 tons

Submerged: 1819 tons

Dimensions

Length: 76.7 metres

Beam: 6.6 metres

Draught: 6.3 metres

Propulsion

Diesel engines: Two MAN M6V 40/46; 2000 hp each

Electric motors: Two SSW 2 GU 365/30; 2500 hp each

Creep motors: Two SSW GW323/28; 113 hp each

Battery: Three 124-cell batteries

Fuel capacity: 250 tons

Performance

Maximum speed

Surfaced: 15.65 knots

Submerged: 16.8 knots

Range

Surfaced: 11150 nm at 12 knots

Submerged: 285 nm at 6 knots

Weapons

Bow tubes: six 21 in(533 mm)

Torpedoes carried: 23

Alternative: 14 torpedoes plus 12 TMC mines

Guns: Two twin 20mm anti-aircraft canon

Officers and Crew: 57

The Electro-boat: Type XXIII U-Boat

While working on the Type XXI design a naval construction director called Oelfken came across the type XXII design by Hellmuth Walter, which was a small coastal U-boat with closed-cycle drive, and considered the possibilities for an electro-boat of about the same size. The idea for a coastal electro-boat was accepted by Doenitz with two provisos, firstly that the design be split up into sections which could be transported by rail and secondly that 7 metre torpedoes be used rather than the 5 metre type favoured by Walter. The coastal electro-boat or Type XXIII had a submerged displacement of 275 tons compared to the 1819 tons of the Type XXI. Like the Type XXI the Type XXIII had a large battery capacity utilising a figure of 8 double-bubble cross section for part of its length. The Type XXIII was a single propeller design with electric and diesel engines of around 600 hp and a creeping electric motor for speeds up to 4.8 knots. The single hull design with a minimal free-flooding volume achieved an underwater speed of 12.5 knots and a snorkeling speed of 10.75 knots. The maximum speed on the surface was less than expected due to a wave coming over the bows greatly increasing resistance and limiting the speed to about 9.7 knots. The design featured a knife-edge stern and a single rudder behind the propeller, and was very manoeuvrable with a small turning circle. Stern hydroplanes were fitted low down in front of the propeller and bow hydroplanes were fitted when it had been established that they were necessary for slow speed manoeuvring. With a small difference between surfaced and submerged displacement, about 41 tons, the Type XXIII could dive very rapidly in about 10 seconds. The normal deep diving depth was about 80 metres.
Originally the submarine was intended to be transported by rail to various ports in German occupied territories, where the sections would be assembled. However following German military reversals, by 1944, it became clear that all the boats would be assembled in Germany. There were 4 sections plus the conning tower. Late in the design stage the boat was found to be too heavy but this was solved by inserting an extra 2.2 metre long section between the control room and the bow section. The Type XXIII had fewer teething troubles than the Type XXI partly because more well-tried components were used. For instance the diesel engine had been used before in diesel generator sets and the electric motor was based on that used in the Type VIIC. The Type XXIII carried only two torpedoes with no reloads. The tubes were loaded externally through the bow caps after trimming the boat down by the stern. The above was a major limitation and a relatively small increase in length would have allowed 4 torpedoes to be carried.
When the war ended on May 8 1945 a total of 62 Type XXIIIs had entered service of which 18 were stationed in Norway and the rest in northern Germany. Ten boats are known to have carried out operational missions sinking five Allied merchant ships, GRT 14,345, for no loss to the attacking submarines.

Specifications

Displacement

Surfaced: 234 tons

Submerged: 275 tons

Dimensions

Length: 34.7 metres

Beam: 3.0 metres

Draught: 3.7 metres

Propulsion

Diesel: One MWN 6-cylinder, 4-stroke RS-34-S unsupercharged diesel; 580 hp

Electric motor/generator: One AEG GU 4463-8 double-armature; 580 hp

Electric creep motor: One BBC GCR-188 single-commutator electric motor; 35 hp

Battery: One 62-cell AFA 2x21 MAL-740E battery; 5400 amp hour

Fuel capacity: 18 tons

Performance

Maximum speed

Surfaced: 9.7 knots

Snorkel: 10.75 knots

Submerged: 12.5 knots

Creep: 4.8 knots

Range

Surfaced: 2600nm at 8 knots

Submerged: 175nm at 4 knots

Crash dive: 9 seconds

Weapons

Bow tubes: Two 21 in (533mm)

Stern tubes: None

Torpedoes carried: Two

Guns: None

Officers and Crew

2 officers, 12 enlisted men