Unknown airfield; defensive position

I am not aware of a water cooled Lewis ever being produced, although the barrel shroud was often mistaken for such.

The first Lewis guns were water cooled which made them too heavy for the early aircraft. When the air cooled gun was developed it was found to be superior in other ways so this model was continued. The cylinders appear to be below the barrels and look more like hydraulic cylinders, I think they are something to do with the counterbalance system rather than recoil as the recoil in machine guns is used to operate the loading mechanism. The objects on the end of the barrels could be there to stop the flash from temporarily blinding the operator.
P.S.As has been said the stroud was later discarded as unneccessary, this may have been the last remnants of the water cooled gun.

Whilst being happy to stand corrected, I can find no evidence of a Lewis gun being provided with water cooling.

The major advantage of the Lewis over the the existing Vickers was it's light weight, of only 12kg; this was due largely to the lack of a heavy cumbersome water jacket.

The guns appear to be MkIII "SS" Lewis Guns, with "Home Guard" modifications, notably the wooden handguard under the gas piston tube and complete removal of both the full and reduced forced-air cooling jackets. They also seem to have the high capacity magazines, I think these held 97 rounds with three dummy followers, but I'd have to check the books for confirmation.
Apparently a lot of these surplus aircraft-pattern Lewis Guns were supplied to the Home Guard for anti-aircraft use, including airfield defence, some sources say US production restarted to supply some under Lend-Lease in addition to those already in WD storage.

All the best,
PB

Yes apparently they were only in widespread regular use in 41-42, after which they were presumably replaced by the BREN etc.
They filled a gap left by the loss of supplies in France.

Standard mag was 47 round, hi cap (intended for aircraft use) was 97 as you say Paul.

Phil, the Lewis was technically gas operated rather than recoil operated.

My dad was a section BREN number 1 in Burma.

From Wikipedia;

"The gun was designed with an aluminium barrel-casing to use the muzzle blast to draw air into the gun and cool down the internal mechanism. There is some discussion over whether the cooling tube was effective or even necessary—in the Second World War many old aircraft guns which did not have the tubing were issued to anti-aircraft units of the British Home Guard and to British airfields, and were found to function properly without it, leading to the suggestion that Lewis had insisted on the cooling arrangement largely to show that his design was different from Maclean's earlier prototypes"

I can't find any reference to the Lewis Gun ever having been water cooled?

Back to the type of gun mount...



Motley Mount Mk5, AKA "Mounting, Seat, A.A." with twin Lewis Mk3s.



Another Motley Mk5, with the seat not installed, fitted to a permanent ground pivot. Twin .303 Brownings.



Motley Mk5 fitted to AAF Jeep, same ammunition feed as in NP's photo. .303 Brownings again.



General layout.



Mounting arm.



As above, with twin Brens.



"Aiming position, with Tracer."



Base arrangement for truck mounting.

All the best,
PB

Does anyone know if the permanent pivot shown in the picture above was exclusively for the use of a Motley mount or whether it could be used for other mounts or weapons