The Skipjack submarine

[rim6o]

Dear developers.
Could you please tell me where did you get the data on the Skipjack submarine?

[Citronvand]

Speaking of Skipjack, why was it nerfed from 33 kts to 30? Currently playing the 68' campaign and there is no reason anymore to pick the Skipjack over the Permit. Permit has 2 wires as opposed to Skipjack's 1, better depth, stealth and sonar. The only thing Skipjack has is measly 2 more kts and 2 more tubes.

[Irving Mainway]

check the credits, they have a list of their source material.

[Irving Mainway]

Originally posted by Citronvand:

Speaking of Skipjack, why was it nerfed from 33 kts to 30? Currently playing the 68' campaign and there is no reason anymore to pick the Skipjack over the Permit. Permit has 2 wires as opposed to Skipjack's 1, better depth, stealth and sonar. The only thing Skipjack has is measly 2 more kts and 2 more tubes.

The Skipjacks were refitted with a slower but quieter 7 blade "skew-back" screw starting in the late 60s. Originally they had a conventional 5 blade screw which was found to have wake turbulance issues.

To try to sum it up pretty quick, at certian sub-cavitation speeds turbulance from the rudder and fairwater would interact with the waterflow over the screw and cause vibration. It doesn't seem like much but on further testing it was the reason that the early SOSUS network was able to track the USS George Washington (which was state-of-the-art for the time) nearly everywhere she went on one of her first deployments. The solution they developed was the skew-back or "Scimitar" screw that was seen on everything from the Permit class on but it was a trade off because it required much finer machining and wasn't as efficient so cut a bit off the top speed.

As far as other advantages of the Skipjack, pretty sure she's still the most manuverable out of the US Subs and should have the smallest active sonar footprint due to her small size.

[Irving Mainway]

https://i.imgur.com/3gGUMZ9.jpg
Old screw as fitted to Skipjack & George Washington class boats on service entry (USS Thresher had one of these too and testing with her is how the vibration issue was identified and understood, she was also reportedly clocked going a good bit faster than the 28 knots her class is rated for).

https://i.imgur.com/q6MO29k.jpg
Skew-back screw on a later Permit class. Nearly all SSNs would have been fitted with this type of screw by the late 60s but AFAIK there was preference given to the SSBNs to make them quieter and I think one Skipjack may have retained the 5-blade into the 70s.