On 5th December, while "U 434" was proceeding up the Portuguese coast, a mast-top was sighted and preparations were made for an attack, but again the U-Boat was thwarted, as the intended victim proved to be Portuguese. A similar false alarm occurred on 8th December, which caused the torpedo rating to write with disgust in his diary: "Again alarm. It is enough to drive you crazy. The crew is fed up".

On 9th December "U 434" is thought to have been off Lisbon and, according to the diary, a number of Spanish ships came alongside on the following day, which caused the writer to make the disappointed comment: "Regret they are friends". There is also a note of frustration in an entry for 11th December, 1941, which runs: "Since this morning attacking strongly guarded convoy. Have not yet fired any torpedoes. This is very tiring". Hopes were finally dashed on the following day when a last entry appears: "Nothing sunk up to this morning (?) o'clock. Lost convoy". (N.I.D. Note - This was Convoy O.G.77.)

It appears that these Spanish vessels reported that some British and American ships were loading in Lisbon. Heyda proposed to lie in wait for them. Dissatisfaction had, however, spread amongst the crew, as they had been without bread and potatoes for five days, so it was decided to put in to Vigo forthwith.

It is believed, from prisoners' statements, that "U 434" arrived at Vigo in the early morning of 14th December, 1941. Apparently the night was so advanced that there was not sufficient time to complete the transhipment of supplies, and Heyda therefore entered Vigo Bay and submerged alongside a German merchant ship. (N.I.D. Note - This merchant ship is presumably the 1,878-ton "Bessel", of the Neptune Line, it having been ascertained that this ship was used for a similar purpose by "U 574" on 13th December, 1941).

As darkness fell on the evening of 14th December, "U 434" rose to the surface and the process of transferring stores and oil from the merchant ship commenced. The cubic volume of oil taken on board is not known, but it is believed to have been considerable. A complete list of stores supplied to "U 434" is contained in Appendix I to this report. A prisoner stated that the provisions were packed in standard size containers and had been purchased in Madrid. He added that one U-Boat was supplied nightly, an allegation that is probably exaggerated, although it is true that "U 574" and "U 434" were provisioned on the nights of 13th and 14th December.

V - LAST CRUISE OF "U 434"

"U 434" left Vigo in the early morning of 15th December, 1941, having remained alongside the German supply ship for approximately 24 hours. According to one prisoner, Heyda had received orders to proceed through the Straits of Gibraltar to a port near Genoa. It is not known whether "U 434" had changed her flotilla at this time, but one prisoner alleged that she had transferred from the "Steuben" U-Boat Group to one known as the "Seeräubern" (Buccaneers).

"U 434" was presumably heading south when she received signals reporting the position of Convoy H.G.76, which had sailed from Gibraltar. The means by which she received these signals has not been divulged, but prisoners from "U 574" stated that they, themselves, picked up reports from Focke-Wulf Kondor aircraft and later from "U 131" (Korvettenkapitän Baumann) which had first sighted Convoy H.G.76 and was shadowing and reporting her position regularly in order to home other U-Boats to the spot before attacking. From whatever source these signals may have emanated, they were stated by prisoners to have been remarkably clear and accurate.

It would appear the "U 434" first received news of the convoy in the evening of 16th December, 1941, and, after proceeding at full speed throughout the night, came up with it on the morning of 17th December, 1941. At this time prisoners believed, as did those of "U 574", that seven U-Boats had assembled for the attack.

At 1330 on 17th December, 1941, when "U 131" was sunk in approximate position 34.03' N., 13.45' W., "U 434" witnessed the incident at extreme range of visibility, estimated at ten miles, and saw shell explosions from "Exmoor", "Blankney", "Stanley", and "Stork". Following the sinking of "U 131" prisoners from "U 434" claimed that four destroyers turned towards and they submerged to periscope depth. The destroyers, however, turned away when they had approached within 6,000 yards and "U 434" followed in pursuit.