SS Blitar was a Dutch cargo steamship that was launched in Rotterdam in 1922 and sunk in the Battle of the Atlantic in 1943.

She is notable for having fought off three u-boats in succession for nearly ten hours before U-632 finally managed to sink her.

In 1921 Bonn & Mees in Rotterdam built the cargo steamship Palembang for the shipping line Koninklijke Rotterdamsche Lloyd (RL).

[2] Blitar, like Palembang, had a three-cylinder triple-expansion steam engine driving a single screw.

In 1931 the P. Smit Jr. [nl] shipyard in Rotterdam added a Brown, Boveri & Cie low-pressure steam turbine to her machinery[2][6] to increase her fuel efficiency and power.

By 17 May German forces had overrun the Netherlands, and on 28 May Blitar left Gibraltar in Convoy HG 32F, which reached Liverpool on 6 June.

[10] On 9 February 1943 Blitar left Buenos Aires for Liverpool carrying a general cargo that included cowhide, fertilizer and food.

[10] On 25 March 1943 Blitar left New York with Convoy HX 231, which comprised 67 merchant ships and 19 naval escorts.

Shells from both vessels fell short, and after six rounds U-229's gun jammed with a shellcase in the breech, so she broke off her attack.

Finally at 0136 hrs U-632 hit Blitar with one torpedo in the starboard side of her engine room, killing 21 of her crew.

Captain Knip volunteered, and having discarded his uniform managed to convince his captors that he was an ordinary seaman.

U-631's commander decided not to keep him prisoner, and sent Knip to swim back to his lifeboat, but he drowned, possibly due to exhaustion.