SM UB-128

UB-148 at sea, a U-boat similar to UB-128.
History
German Empire
NameUB-128
Ordered6 / 8 February 1917
BuilderAG Weser, Bremen
Cost3,654,000 German Papiermark
Yard number301
Laid down20 July 1917
Launched10 April 1918
Commissioned11 May 1918
FateSurrendered 3 February 1919; used for explosive trials and dumped on beach 1921; sold for scrap 1921
General characteristics
Class & typeType UB III submarine
Displacement
  • 512 t (504 long tons) surfaced
  • 643 t (633 long tons) submerged
Length55.85 m (183 ft 3 in) (o/a)
Beam5.80 m (19 ft)
Draught3.72 m (12 ft 2 in)
Propulsion
Speed
  • 13.9 knots (25.7 km/h; 16.0 mph) surfaced
  • 7.6 knots (14.1 km/h; 8.7 mph) submerged
Range
  • 7,280 nmi (13,480 km; 8,380 mi) at 6 knots (11 km/h; 6.9 mph) surfaced
  • 55 nmi (102 km; 63 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth50 m (160 ft)
Complement3 officers, 31 men
Armament
Service record
Part of:
  • Mittelmeer I Flotilla
  • 4 September – 11 November 1918
Commanders:
Operations: 2 patrols
Victories: 1 merchant ship sunk
(7,418 GRT)

SM UB-128 was a German Type UB III submarine or U-boat in the German Imperial Navy (German: Kaiserliche Marine) during World War I. She was commissioned into the German Imperial Navy on 11 May 1918 as SM UB-128.

UB-128 was surrendered to the Allies at Harwich on 3 February 1919 in accordance with the requirements of the Armistice with Germany. After passing into British hands, UB-128 was towed to Falmouth along with five other U-boats for use in a series of explosive test trials by the Royal Navy in Falmouth Bay, in order to find weaknesses in their design. Following her use on 1 February 1921, UB-128 was dumped on Castle Beach and sold to R. Roskelly & Rodgers on 19 April 1921 for scrap (for £120), and partially salvaged over the following decades, although parts remain in situ.