Historical Endurance of Type IX?
 

Apologies if this is the wrong section to post this question first of all, but:


In an effort to enhance realism, I've decided to try to only stay on patrol as long as my chosen U-boat type (type IXA) would allow for in terms of stores (foodstuffs, etc.)



The problem is, while I can find the operational endurance of US fleet boats in WW2 fairly easily, (56-60 days,) the same data for a type IX is harder to come by. I can find range at speed fairly easily, but that's not what I'm looking for.


And yes, I'm aware of the "Milk Cow" boats used for resupply during the war. I'm trying to find the operational endurance of a type IXA without a resupply.


Anyone happen to know this information off the top of their head? and if not, perhaps where I could find this information?

That’s a good question, without resupply I’m not sure. I would say though that uboat.net would be a good place, I would scour the IXs in there, the patrols that they went on, just to get a feel for the length of time and be able to see whether or not any resupply happened.

My initial hunch though is anywhere from 50 to 60 days.

There were 8 boats of that type Type IXA (or just Type IX):
U-37 longest war patrol 41 days

U-38 longest war patrol 82 days

U-39 longest war patrol 27 days (sunk during patrol)

U-40 longest war aptrol 31 days

U-41 longest war patrol 31 days

U-42 longest war patrol 12 days (sunk during patrol)

U-43 longest war patrol 82 days

U-44 longest war patrol 35 days


On the other hand, other Type IX boats like the IXB and the IXC did even longer patrols like U-161's longest patrol was 113 days and U-196 (Type IXD) did two long patrols, one 148 days and one with 225 days (longest patrol of WW2, IIRC). U-105 (Txpe IXB) had war patrols ranging between 36 and 112 days length.
So a patrol length between 30 days and 100-120 days would be ok.