U 3505 was a German U-boat U-boat Class XXI, which was used during the Second World War by 
the German Navy. It was planned for use in the Atlantic. 

U 3505 was the seventh after his entry into October 1944 except to torpedo exercises being 
used for combat missions. 

The only official missions were of 7 October 1944 to 15th 8th February 1945, the company 
Flotilla during a training cruise and then 16 February 1945 to 3 April 1945 (planned) the 
training cruise in the 5th U-Flotilla. The latter was carried out but not until the end but 
on 27 March aborted. 

U 3505 was known as a refugee boat. His commander Oblt.z.S. Horst Willner was contrary to 
the provisions for the submarines 28th March 1945 his wife Ursula disguised as a sailor and 
his three-month-old daughter Barbara, who was hidden in a duffel bag, brought on board and 
hid in his cabin. This family was in favor of military law, the death penalty. Will former 
family should flee to the Wilhelm Gustloff, however, Horst Willner decided to return the 
reserved places, thus saving the lives of his family, as the Wilhelm Gustloff was sunk a 
short time after the expiry of a Soviet submarine. 

After leaving the Port of Gdansk, Gdynia, the boat headed toward the west, where 110 children 
and adolescents commander Willner, mainly members of the Hitler Youth took on board. The 
journey continued on Bornholm, where the supplies were replenished on board, to Lübeck-Travemünde. 
There, the refugees went on 2 April 1945 board, including the family of Horst Willner. 

The crew steered the boat still in the port of Kiel, where U 3505 should attend torpedo exercises. 
It never came but no more. On 3 April 1945, at 17.25 clock the boat was in an Allied air raid of 
the 8th Air Force of the USAAF on keel sunk by a hit on the port side. Here, the radio operator of 
the boat was fatally wounded. All other crew members survived, because the boat at the time of the 
attack was only occupied by four men guards. 

Ref:http://de.wikipedia.org/wiki/U_3505