|"U" class Coastal Submarines|
by German Minesweepers M.1201, M.1204
& M.107 off
Heligoland, scuttled, 7/1/40
|Unity||66C||Vickers||5/10/38||Colided with mercantile Atle Jarl off Blyth, 29/4/40|
|Ursula||59C||Vickers||20/12/38||To Soviet Union as B.4, 1944. Returned 1949 & scrapped|
|Umpire||82N||Chatham RDY||10/7/41||Rammed in error by trawler Peter Hendriks off The Wash, 19/7/41|
|Una||87N||Chatham RDY||27/9/41||Scrapped 1949|
|Unbeaten||93N||Vickers||10/11/40||Bombed in error by RAF in Bay of Biscay, 11/11/42|
|Undaunted||35N||Vickers||30/12/40||Probably mined off Tripoli, c. 7/5/41|
|Union||56N||Vickers||22/2/41||Depth-charged by Italian motor boat Circe off Pantellaria, 20/7/41|
|Unique||95N||Vickers||27/9/40||Loss unexplained off Gibralter, c. 10/10/42|
|Upholder||99N||Vickers||31/10/40||Depth-charged by Italian motor boat Pegaso off Tripoli, 14/4/42|
|Urchin||97N||Vickers||28/1/41||To Poland as Sokol, 1942. Returned 1946 & scrapped 1949|
|Urge||17N||Vickers||12/12/40||Bombed by Italy in Eastern Mediterannean, 29/4/42|
|Usk||65N||Vickers||11/10/40||Probably mined off Cape Bon, c. 26/4/41|
|Utmost||19N||Vickers||17/8/40||Depth-charged by Italian motor boat Groppo off Marittimo, 25/11/42|
|P32||P32||Vickers||3/5/41||Mined off Tripoli, 18/8/41|
|P33||P33||Vickers||30/5/41||Probably mined off Tripoli, 15/8/41|
|P36||P36||Vickers||24/9/41||Bombed by Luftwaffeoff Sliema, 1/4/42. Salved 8/7/58 & scrapped|
|P38||P38||Vickers||17/10/41||Depth-charged by Italian motor boat Circe off Ras Misurata, 23/2/42|
Luftwaffe in Valetta, 26/3/42, written off. Salvaged then
in Kalkara creek, ?/6/43, scrapped 1954.
|Uredd||P41||Vickers||12/12/41||Royal Norwegian Navy, mined off Bodø, 10/2/43|
|Unbroken||P42||Vickers||29/1/42||To Soviet Union as B.2, 1944. Returned 1949 & scrapped 1950|
|Unison||P43||Vickers||19/2/42||To Soviet Union as B.3, 1944. Returned 1949 & scrapped 1950|
|Dolfijn||P47||Vickers||8/10/42||Royal Netherlands Navy, scaspped 1952|
|P48||P48||Vickers||18/6/42||Depth-charged by Italian corvette Ardente off Zembra Island, 25/12/42|
To Denmark 1946 as U.1, then Springeren
1957 & scrapped.
|Usurper||P56||Vickers||2/2/43||Depth-charged by German trawler Uj.2208 in Gulf of Genoa, c. 11/10/43|
diving accident off Cambletown, 30/5/43. Salved 5/7/43
Vitality, scrapped 1946
|Untiring||P59||Vickers||9/6/43||To Greece as Xifias,
1945. Returned 1952 & expended as target off Start
|Vandal||P64||Vickers||20/2/43||Wrecked in Kilbrennan Sound, 24/2/43|
|Upstart||P65||Vickers||3/4/43||To Greece as Amfrititi,
1945. Returned 1952 & expended as target off Isle of
|Varne||P66||Vickers||3/4/43||To Norway as Ula, 1943. Scrapped 1966|
|Vox||P67||Vickers||2/5/43||To France as Curie 1943. Returned 1946 & scrapped 1949.|
* = Armament & Displacement variation, see tables
|1:600 HM s/m Undine,
"U" class group 1. The lack of a deck
gun and the bulbous nose housing the external torpedoes are
visible here. This casing was found ( like in the "T" class ) to
impair vision at periscope depth and was only found on 7 "U"
class of all groups. © Andrew Arthur
|1:600 HM s/m Ursula,
"U" class group 1. She was the only member
of the first goroup to have a deck gun, a 12pdr. AA gun.
Unfortunately, there was no hatch to serve this weapon, and it was
a race against time to get all crew up the conning tower and into
that hatch during a crash dive! © Andrew Arthur
|1:600 HM s/m Upholder, one
of four "U" class group 2 submarines
to retain the bulbous bow & torpedoes. The deck gun was a 12pdr.
AA, but this group did have a deck-gun hatch.© Andrew Arthur
|1:600 HMS s/m Una, of the
main batch of "U" class group 2. The
external tubes were removed and replaced with a fined off, raked
casing forwards.© Andrew Arthur
|1:600 "U" class group 3.
The casing was fined off at the end, to
allow for quieter, more efficient steaming. The gun was a 3"
low-angle type. © Andrew Arthur
This class was originally designed as an
unarmed "H" class replacement, for training both
submarine crews and escort teams, but early in their development
it was decided to arm them to make them capable of short war
As such, the first group of three units was armed with four internal and two external 21" torpedo tubes. The external tubes were in a bulbous casing like the early "T" class, and the same problems as the latter stemmed from this : at periscope depth, the casing created a large wake, and this obscured periscope view forward. In addition, Undine fitted a 12pdr AA gun in-front of the conning tower. The only problem with this was that there was no special gun hatch, and it was with a great struggle that the gun crew and ammunition got out the conning tower hatch in a rush, that the gun was supplied with ammunition with a full bridge watch, and that in a crash dive, both the birdge & gun crews and all the ammnition got back down the hatch in a hurry!
Single hulled construction was opted for, all ballast and fuel being carried internally, and a casing covered the fore ends of the full for about 3/4 of it's length, tailing off after the conning tower.
To simplify ( and compact ) machinery arrangements, they adopted diesel-electric surface drive; the diesels were permamnently connected to the generators, and for surface power, the motors were run straight from the generators. This meant no bulky, complex and hard to produce gearing & reversing arrangements were needed, and particualarly in war, gearing jigs took a long time to manufacture and get into production.
At the out-break of WW2 the three first class units were put into action, and were extremely successful in the shallow confines of the Mediterranean, Norwegian Fjords and the coastal waters of the UK.
Because of their success, they were put right back into production, and the second group differed mainly in having a permamnent deck-gun and gun hatch, and after the first four units, no bow tubes, and a fined, raked casing forwards. Also, uprated diesels and generators were fittted, and propulsion was quietened and made more efficient by adopting finer, better machined propellors. The third group had a slightly lengthened after casing for smoother surface running.
As already mentioned, they were very succesful. Being very simple to manufacture ( compared with German and Italian submarines, they were very dated ), a real bonus in wartime and easy to train crews for ( particualarly those of the Free French, Greek, Norwegian & Netherlands navies, and the Soviet Union ). Aslo, being around in large numbers, they could absorb a disproportionate amount of the enemy's ASW resources.
It was the inshore waters of the UK & Norway and the confines of the Mediterannean that was their hunting grounds, always being fairly close to home ( never more than two days sailing from base ), their small size allowed them to work close inshore undetected, and although they were not very significant themselves, as a cxlass they were..
Being small however, conditions aboard were far from comfortable, one veteran describing a term in naval detention barracks a holiday compared with the forends of a "U" class submarine.
After the war in Europe ended they were quickly relegated back to training, and soon paid off and scrapped, or passed onto other Navies.
|Group 1||Group 2||Group 3||Group 1||Group 2||Group 3|
|Empty Displacement||540 tons||545 tons||540 tons||Length||191'||192.25'||196.75'|
|Surfaced Displacement||578 tons (*=594)||586 tons||581 tons||Beam||16'||16'||16'|
|Submerged Displacement||730 tons||735 tons||730 tons||Draft||12.75-14.5'||12.75-14.5'||12.75-14.5'|
|Performance & Propulsion|
|Group 1||Group 2||Group 3|
|3800 nm @ 10 kts = 37 days|
|11.75 kts ( 10 kts submerged )||12 kts ( 9 kts submerged )|
6cyl. Paxman-Ricardo diesels @ 615 bhp,
2 x generators @ 450 kW,
2 x GEC electric motors @ 825 shp
|2 x 8cyl. Paxman-Ricardo diesels @ 800 bhp,
2 x generators @ 600 kW,
2 x GEC electric motors @ 825 shp
|Armament & Complement|
|Group 1||Group 2||Group 3|
|5 officers & 22 ratings (* = 6 + 27 )||6 officers & 25 ratings|