B1 submarines (1922-1926)


B6 1930


Name No Yard No Builder Laid down Launched Comp Fate
B1 (ex-A4)     SECN, Cartagena 2/1917 2/6/1921 2/1922 stricken 10/1941
B2     SECN, Cartagena 8/1917 1/10/1921 6/1922 stricken 5/1951
B3     SECN, Cartagena 1/1920 18/3/1922 8/1922 stricken 6/1940
B4     SECN, Cartagena 5/1920 31/10/1922 5/1923 stricken 7/1941
B5     SECN, Cartagena 1/1921 4/1/1925 12/1925 lost 12-16/10/1936
B6     SECN, Cartagena 9/1921 6/6/1925 1/1926 sunk 19/9/1936

Technical data

Displacement standard, t 
Displacement normal, t

556 / 740

Length, m

62.5 pp 64.2 oa

Breadth, m


Draught, m


No of shafts



2 Nelseco 8-cyl diesels / 2 electric motors

Power, h. p.

1400 / 420

Max speed, kts

16.2 / 10.5

Fuel, t

diesel oil 81

Endurance, nm(kts)

8000(10.5) / 125(4.5)


4 - 450 TT (2 bow, 2 stern, 8)



Diving depth operational, m60


<i>B6 </i>1930
B6 1930

Ship project history

First combat Spanish-built submarines, built according to the law from 17/2/1915 under the licence and with assistance of Electric Boats Company under design "Holland 105F". They were ordered 7/2/1916. B1 in building was named A4. Single-hulled. Rather perfect and successful ships for time, by 1936 they became outdated and had big deterioration of hulls and machineries. Maximal diving depth under the design was 60m, to Civil war it actually did not exceed 20-25m.


1928, all: + 1 x 1 - 76/45 Vickers Mk SS

Naval service

All boats in 1936 remained under control of Republicans. B1 and B2 since late 1937 were laid up into reserve at Cartagena because of bad technical condition. B3 in December, 1936 was hard damaged as result of collision with Norwegian s/s Frank, repair in Cartagena lasted till the end of war. B4 in December, 1936 was damaged by aircraft of Nationalists at Malaga, she passed to Cartagena for repair, but 15/3/1937 was stricken from Republican fleet. At agony of Republic in the end of March, 1939 these four submarines were foundered on shallow water: B1 and B2 at Cartagena, B3 and B4 at Portman near Cartagena. All were soon salvaged by Nationalists, but never commissioned again and sold for scrap, except for B2, used till 1948 as a TS (without diving ability), and since 1948 as battery charge plant at Ferrol. B1 was used as target and sunk in 1949. B5 was lost in strait of Gibraltar: she was sunk by seaplane of Nationalists 12/10/1936 or scuttled 16/10/1936 by her commander sympathising to Nationalists. B6 19/9/1936 at Cape Peñas was sunk by gunfire of Nationalists destroyer Velasco and armed tug Galicia with assistance of sympathising to Francists commander of submarine.