1936B type destroyers

Nazi Germany: 1936A and 1936A mob: Z23-Z39 (Built 1938-1943)

The Type 1936B destroyers (Z35 class) were the last Kriegsmarine wartime destroyers. They were laid down between June 1941 and September 1943 and due to the wartime difficulties encountered by the conderned yards (Deschimag in Bremen and Germaniawerft in Kiel) only three ships out of the eight ordered were commissioned, two were never completed and three were cancelled on 1940. None the following Type 1936C were ever completed. Technically, they were follow-up class virtually identical but with better FLAK and no twin turret (back to five single main guns), as well as good radars from the start. It seems also their troublesome Wagner turbines an boilers had been refined enough for them to be more reliable at this point, for a short service overall. At this stage of the war, All three operational destroyers never ventured out of the Baltic Sea, escorting German convoys or laying minefields and shelling Soviet forces in 1944–1945 as they progressed in eastern Prussia. Z35 and Z36 were lost in the Gulf of Finland in their own minefield by late 1944, Z43 was scuttled before May 1945. #zerstoerer #kriegsmarine #ww2 #destroyer #germannavy

Z43 on trials. Unfortunately there are few CC photos

Design History

Final design

The Z35 class or Type 1936B evolved from the Type 1936 and 1936A, and fixed seaworthiness issues with new prows and bow shapes, better flare, reworked transom stern, but saukeil eliminated and better counterkeels fitted. They were a repeat of the 1936A without the forward twin turret, which was both heavy, finnicky and costly to produced, returning to the classic arangement of four single pasked main guns. They also repeated the same machinery of their precedessors which seems less troublesome due to wartime experience and constant improvements. The armament was beefered up considerably in terms of FLAK (AA) with the “barbara” upgrade integrated from the start. Also were advanced radars. In fact, they were not modernized during their service.

So the 1936B share the same hull as the 1936C but carrying a lighter armament of five 128 mm/42 instead of 15 cm as in the previous class. This was due to several factors, notably the shortage of these new 15 cm caliber, but also of weight (97 tons for the turret alone). To keep the weight down while added radars and heavier FLAK, it was needed to reduce top wieght and returning to a smaller calober was sich logical move. The previous class already was plagued by the shortage of C38 twin turrets, delayed by production difficulties, and part of the class was completed with a single 150 mm mounting on a bandstand. Plus the 15cm gun proved to be less than satisfactory as the ammunition was made of heavy separate shells and powder-cartridges instead of the single cartridge of the 12.7 cm. The sea-going capabilities of the 1936A suffered, and the errors was not to be repeated on the 1936B, neither for the 1936C which instead went to brand new lightweight twin turret (three twin arrangement) with brand new dual purpose 12.8 cm (5 in) Quick-firing guns.

Construction

Hull and general design

The 1936B type destroyers were of the same size as the 1936A for buoyancy reserve and stability concerns. The previous class was planned to carry much heavier 15 cm guns so by reversing to a lighter caliber it was logical to believe this would improve stability and allow for the addition of copious AA. They ended at lighter as a result than the 1936A with 2,519 long tons (2,559 t) standard and 3,542 long tons (3,599 t) deep load versus 2,543–2,657 long tons (2,584–2,700 t) and 3520-3590t fully loaded. They were as long as the previous class, at 127 m (416 ft 8 in) overall same beam at 12 m (39 ft 4 in) and reduced draught at 4.32 m (14 ft 2 in) versus 4.38–4.65 m (14 ft 4 in – 15 ft 3 in). Metacentric height is unknown.

Protection consisted in the seame hull compartimentation, subdivision below the waterline into 16 watertight compartments, double bottom over 47% of their length amidships. Seven compartments amidships contained the propulsion and auxiliary machinery. Their crews amounted to 335 officers and sailors sailors but they still could act as flagship with 4 extra officers and 19 sailors. The bridge outlook was unchanged and however the roof was reinforced to support larger aerials.

For the rest, same design, with the flat, “cross” bridge face with wings extensions, open roof bridge, small structure aft to house and support the fire control, raked tripod mainmast, large main funne, capped for four exhausts (forward pairs of boilers), first torpedo tube bank, amidship structure with aft capped raked funnel for the aft pair of boilers. Aft searchlight on platform, right behind, second forward placed high up on the tripod mainmast.
Aft torpedo tubes bank, rear quartedeck house supporting two 12.8 cm single turrets X, Y, plus Z further aft on deck. X faced forward as in previous designs and in between was located the small radio house topped by a Flakvierling mount. Platforms were created to mount heavy AA all across the ship.
The hull had the same clipper bow with quite a bit of flare forward, gradual beam profile, limited flat section amidship, broad transom stern. All-metal deck with wood still used on the bridge’s wings and upper open bridge deck. No longer four boats were carried for the crew to maje room and free arc of fire, and instead live vests and rafts were produced and stacked wherever possible.

Powerplant

The Type 1936B destroyers had the same powerplant as the 1934/1934A/1936 types but with Wagner geared steam turbine sets driving three-bladed 3.25-meter (10 ft 8 in) propellers. Steam came from six high-pressure Wagner water-tube boilers fitted with superheaters, but the big difference here to improve reliability is that they dropped temperature of a steam (426°С instead of 460°С) and lower working pressure at 70 atm (7,093 kPa; 1,029 psi). Still, they were noted for an ouput of 70,000 metric horsepower (51,000 kW; 69,000 shp) and a top speed of 36 knots (67 km/h; 41 mph) with better results on trials.

They also carried much more fuel than previous classes, a maximum of 835 tonnes (822 long tons) for a range of 2,600 nautical miles (4,800 km; 3,000 mi) at 19 knots (35 km/h; 22 mph) versus 739 metric tons (727 long tons) of fuel oil for 2,050 nautical miles at 19 knots on the 1936A, quite an improvement overall, especially compared to the 1934A (1,825 nmi), but les impressive compared to the Mobilization type, carrying 825t of oil for 2,950 nautical miles at 19 knots.
When the boilers were cold, to power AA and other systems they still hae a pair of 200-kilowatt (270 hp) turbogenerators and two 80-kilowatt (110 hp) diesels as well as single 40-kilowatt (54 hp) diesel generator located amidship.

Armament

Like the 1934/34A, 1936, they had five main guns, but the FLAK was greatly improved. They kept their two quadruple torpedo tubes and could lay up to 60 mines. ASW armament was completely absent at first but later four depht charge throwers were added aft. The five main guns were shielded 12.7 cm (5 in) SK C/34 guns in single mounts: Superimposed pair A-B forward, same aft, 5th mount positioned on top of the rear superstructure, facing forward. 600 rounds between them.

12,7-cm-Schnelladekanone C/34

The Z1 class had five 12.7 cm (5 in) guns (a rather standard caliber for the time). These were all shielded, in single mounts: Two superimposed forward, three aft incuding two facing aft, one superfiring, and one facing frorward, the intermediate N°3 mount. For these, they carried 600 rounds of ammunition.

The anti-aircraft armament (FLAK) comprised the following:
-Two twin 3.7 cm/80 SK C/30 (1.5 in) anti-aircraft guns (8,000 rounds of ammunition)
-Three quad (Flakvierling), three single 2 cm/65 C/38 (0.79 in) anti-aircraft guns, (16-20,000 rounds of ammunition).
Mounts were stabilized, with gyroscopes better adapted this time to cope with sharp turns or heavy rolling.

3,7-cm/80 Schnelladekanone C/30

The C/30 was a semi-automatic anti-aircraft gun automatic ejection of spent cartridge casing but hand-loaded one round at a time for up to 30 rounds per minute. It was well below the Bofors 40 mm whereas its muzzle velocity was 12-15% higher with better aiming. It was ubiquitous in the Kriegsmarine. These were power operated mounts with a maximum elevation of 85° for a ceiling of 6,800 metres (22,300 ft).
Specs:
Mass: 243 kgs (536 lb), 3.074 metres (10 ft 1 in) long, 2.962 metres (9 ft 9 in) L/83 barrel
Fired a fixed, 0.68 kilograms (1 lb 8 oz) cased charge shell 37 x 380 mm R
The breech was a semi-automatic, vertical sliding-block type allowed 30 rpm (practical)
Muzzle velocity was 1,000 m/s (3,300 ft/s) 2,000 m (6,600 ft) effective ceiling and 8,500 m (9,300 yd) at 37.5° max.

2-cm/65 Schnelladekanone C/38

The rival to the allied oerlikon, this ordnance was developed and manufactured by Rheinmetall, a design linked to the earlier Solothurn ST-5 and declined int the C/30 and the C/38, both fully automatic. The C/30 was prone to jamming using a 20 rounds magazine with frequent pauses for reloading. The C/38 had a short recoil and the same 20-round magazine with a later 40-round magazine introduced, more reliable overall. The Navy mount was a tri-axial quad system develped for the C/30 guns with layer and pointer in front, cross-roll operator behind (Flakvisier 35 gunsight) and later evolved into the 2 cm Flak C/38 auf Vierlingslafette C/38 with a simplified bi-axial quad mounting (Flakvierling 38) operated by a single gunner behind. But these were single mounts in the earlier case, with c/38 guns here. Later Flakvierlings were installed (Barbara upgrade)
Specs:
C/38 weight 129 lbs. (57.5 kg) oa lenght 88.7 in (2.2525 m) barrel 51.2 in (1.300 m)
Rate Of Fire 480 rounds per minute cyclic, 220 rounds per minute practical
0.71 lbs. (0.320 kg) round, either AP-T 0.326 lbs. (0.148 kg), HE-I 0.265 lbs. (0.120 kg) or HE-T 0.256 lbs. (0.116 kg)
Complete round 8.99 in (22.8 cm) with 0.265 lb. (0.120 kg) RPC/38 propellant, Brass, 20 x 138B mm, 0.41 lbs. (0.186 kg)
Muzzle Velocity from 2,625 fps (800 mps) to 2,870 fps (875 mps) with HE-T.
2,000 rounds stored for each in 20-rounds mags (200 mags).

G7a torpedo Torpedoes

They had eight 53.3 cm (21 in) torpedo tubes, in two quadruple, centerlined in electrically power-operated mounts. They had reloads, obut only four torpedoes, two for each bank.
They were of the 1934 53.3 cm (21″) G7a T1 “ato” class. read more

Mines

Each of the 1936A and (mob) had mine rails fitted fitted on the rear deck with a capacity of 74-76 mines total, more than the 60 on previous class. They are assumed to be the EMC Contact Mines placed on trolley rails. These were spherical mines 44 inch (1.12 m) in diameter and with an explosive load of 661 lbs. (300 kg). Detonation was trusted to seven Hertz horns. These mines could be moored underwater, under 55, 109, 164 or 273 fathoms (100, 200, 300 or 500 m). First captured by the British in October 1939. more on navweaps.com/

ASW

Four depth charge throwers were mounted on the sides of the rear deckhouse, plus six racks for individual depth charges on stern sides. This was caluculated for two or four patterns of sixteen charges each. They also came out with the ‘GHG’ (Gruppenhorchgerät) passive hydrophones, fitted underneath the hull, to detect submarines.
These four stern Wasserbombenwerfer C/35 depth charge projector located on the broadsides close to the freeboard to clear mine rails fired a Rheinmetall 606 lbs. (275 kg), initial velocity of 115 fps (35 mps) and an arbor weight of 77 lbs. (35 kg). In total they could carry as high as 64 depth charges charges.

Fire Direction and sensors

The Type 1936B had the same fire control systems as for the Type 1936A (mob), between the bridge, masts, and aft on the amidship structure. They consisted in a large telemeter connected to a ballistic calculator with data transmitted to each gun via intercom and indicators to coordinate fire on a single target at once. For ASW work they had the ‘GHG’ (Gruppenhorchgerät) passive hydrophones and an S-Gerät sonar. More so, they were equipped with a FuMO 24/25 radar set above the bridge.

FuMO 24/25 radar

This upgraded system dated from 1944. It had a larger bedframe antenna 2 x 6-meter (6 ft 7 in × 19 ft 8 in) and slightly better range.
Specs: 8 kW, Frequency 368 MHz/81.5 cm, PRF 500 per second, Pulsewidth 5 μs
Range: about 12 nmi (22 km; 14 mi) prec ±70 m (230 ft)

FuMB 3 Bali ECM suite

The first serial ECM suite on Kriegsmarine ships, it consisted of a cylindrical bedframe antenna located atop the main battery director. On larger ships ideal combinations were of the FuMB 9 (W. Anz.g.2), FuMB 4 (“Samos”) and the FuMB 10-FuMZ 6 (Borkum-naxos combination) search receivers.
In general these symmetrically fed broadband round dipole had a range around 90 to 500 MHz and were pressure-waterproof with towering rods receiving vertically polarized waves. In this case, the dipole halves are short-circuited on the receiver side and used as a counterweight for the support mast. FuMB 3 was also mounted on submarines.

FuMB 6 Palau ECM suite

A complementary, larger set. This antenna was placed on the foremast spur above the Fumo 21/24 bedframe radar. The masthead top had the lighter FuMB 3 Bali.
In 1944 usually a FuMO 63 Hohentwiel-K replaced the aft searchlight on its platform, and a FuMB 6 Palau on a yardarm was found of the foremast with a passive array consisting of four fixed Sumatra dipoles situated around the forward searchlight sponson.

S-Gerät sonar

This device could be inclined 80 up and down and also sideways and was stated to have a range of 400 metres. This was the standard light sonar common to light vessels and U-Boats.

GHG hydrophone

The GHG for “Gruppenhorchgerät” was originally designed for U-boats and included two groups of 24 sensors each with its own tube preamplifier for frequency signals routed to a switching matrix in the main unit. The sonar operator could then detect exact direction of the sound source. Often three switchable crossover with 1, 3 and 6 kHz center frequency were used. it had a dead zone fore and aft however and a range of 20 km. The Resolution was below 1° at 6 kHz, 1.5° at 3 kHz, and 4° at 1 kHz without crossover of 8°.

Combat Records

The only three completed ships, Z35, 36 and 43 ended in the 6. Zerstörerflotille (6th Destroyer Flotilla) operating in the Baltic in 1944 and tasked to support minelaying missions, notably in the Gulf of Finland by February 1944, escorting convoys before. The first minefield were laid in mid-March 1944 and this went on until July, as well as reinforcing existing minefields in the Gulf of Finland. Z36 was versed to their unit by late June and thi main task became shelling advancing Soviet positions at the end of July and escorting heavy cruisers doign the same. This went on until the end of the war. In September they started also to escort convoys evacuating German forces from Finland and Estonia.
By mid-December theu laid down a new minefield between the Estonian coast and another minefield further out to sea but bad weather and poor navigation skills led Z34 and 36 to blunder into the latter minefield. At 02:00 not hit mines, Z36 wen,t down quick, Z35 lasted a longer and c70 men were rescued by the Soviets and sent to Gulag. Remaining Z43 escorted convoys in 1945 alternating with shore bombardment until hitting a mine on 10 April. She had emergency repairs and was stuck in Warnemünde harbour providing gunfire support, leaving on 2 May for Kiel out of ammunition, scuttled the following day to avoid capture.