Lockheed Ventura Mk I and Mk II differences

[Larry]

Guys with regard to the RAF Lockheed Ventura Mk I and Mk II what were the differences?

I know that the Mk II had a Pratt & Whitney R-2800-31 Double Wasp, rated at 2,000 hp, which I think was the same as the USN PV-1

I cannot find the P&W Double Wasp engine type for the Mk I.

What other differences were there between Marks, as the defensive armament looks to be the same ?

Lastly, was there an official designation for the Ventura Mk II which had a Bolton-Paul Mk IV four gun turret, fitted in place of the earlier egg shaped BP two gun turret. While I have seen these BP Mk IV turrets in use on the Venturas in the Med, no author has picked up the type or the fact that they were used in the UK, in 2 Group such as this in the attached photo while serving in 464 Sqn, when the Queen (Mother) paid a visit.

Perhaps Mk IIB might have been used?

[Graham Boak]

The Mk.Is were powered by 1850HP P&W Double Wasp S1A4-Gs, which were built to commercial standards. The Mk.IIs were powered by 2000hp R-2800-31s built to US military standards. Information from Putnam's Lockheed Aircraft since 1913, by Rene J. Francillon.

The RAF would normally change the mark numbers because of significant changes such as engines, wings, radars. They would not change them because of the armament, although sometimes (rarely) such things would be noted as series i, series ii, etc. I know of no such change to the Ventura. To be honest, it is only a few years since Tony O'Toole pointed this out on this forum, and presumably in his articles on the Ventura in modelling magazines. I'd not seen it mentioned elsewhere before then.

[Stig Jarlevik]

Larry

Checking my books I think the main difference were the engines

Mk I 2 x 1850hp P&W Double Wasp S1A4-G
Mk II 2 x 2000hp P&W R-2800-31

The Mk II also had a redesigned bomb bay to carry a heavier bomb load.

The Mk IIA featured a Martin turret
Never heard of any "Mk IIB" so whatever modifications were made post delivery probably never really made it into its Mk designation.

Cheers
Stig

[Larry]

Thanks all

[Zoran Petek]

Hello all,
It's all known for decades, and there are many photos at the IWM,
and is also recorded at films such as 21 Sqn's
https://www.youtube.com/watch?v=a6WdixgpWqs
or 464 Sqn's
https://www.youtube.com/watch?v=lPKZL4FylLM
Missions and serials for 25 Sqn SAAF can be found at
http://www.maketarstvo.net/forum/vie...a2959f4518cd53
Also French PV-1s

Zoran

[Graham Boak]

Lots of things are available (somewhere) in photos or records without having been pointed out in print. None of your links are to anything widely or easily available to the general enthusiast before very recent years.

It isn't clear to me why PV-1s should be mentioned, as these certainly didn't have the Boulton Paul A turret that Larry was asking about, and I rather doubt that 25 (SAAF) Sq's aircraft did either.

[Zoran Petek]

Why point to something obvious? AE847 SB-N, below.
AWM via http://adf-serials.com.au/ventura.htm

[Larry]

I pointed this out as Ventura Books do not include any mention of the BP Mk IV four gun (0.303) turret in use by the Squadrons of 2 Group RAF in 1943, despite as you say the information being so readily available in photos. Obviously I can understand this for authors from the pre-internet days but not anything printed since!

[Zoran Petek]

Hello all.
Larry, You may ask anything You like at this forum, about known or unknown subjects.
I was provoked by Graham's dogmatic approach.


Ventura Mark I AE686
As delivered, no turret. Later (with turret installed) served with 21 Sqn RAF.



Standard 2-gun turret



Ventura Mark I AE660 YH-Y of No. 21 Squadron RAF.



Lockheed Venturas and aircrew of No 464 Squadron, RAAF, at Feltwell, December 1942.



SB-H - the same aircraft is in Larry's image.

Regards to all

Zoran