ID guns on these MCC trucks

[Mike Cecil]

Gun, QF, 18-pdr Mk.1(P).

ie, a WW1 era Mk.1 18-pdr, 'pneumaticised' by convesion to pneumatic wheel/tyre combinations with high-speed axle with ball-type wheel bearings.

A salient feature is the single pole-trail.

Mike C

[Mike Cecil]

correction: cone-and-roller type wheel bearings.

QF is Quick Firing: ie the means of obturation is the expansion of the brass shell case against the breech. Ammunition was fixed type.

Gun had a comparatively low range of the angle of fire (+/_ horizontal): quite a contrast to its replacement, the 25-pdr 'gun-howitzer', which was much more versatile.

Mike C

[chrisgrove]

Pole trail limits elevation - hence reduces the range! Nice pics of Martin Parry conversion.

Chris

[Mike Cecil]

Yes, that's partly true, but there comes a point of elevation with a fixed cartridge (like the 18pdr) where further increasing the elevation actually decreases the range. I agree that the single pole trail design limited the elevation in the 18pdrs case to only +16 degrees, which in turn meant that for the 18pdr cartridge, the maximum range attainable was also limited.

The main problems with the limited range of elevation (-5 to +16 degrees on the 18 pdr Mk1) were crest clearance (getting a round over elevated terrain) and the inability to elevate sufficiently for 'plunging fire', ie getting the round coming back to earth at a high angle, which was much more effective when bombarding emplacements and fortifications.

Mike C

[Mike K]

Wiki does it again:

http://en.wikipedia.org/wiki/Ordnance_QF_18_pounder

Nasty , the way the shell exploded, delivering a wave of lead/antimony bullets up to 300 yards away .

Mike

[Mike Cecil]

Yes, Mike: I've just read through it, and its a good coverage of the gun and ammunition. Not much reference to Australia (esp WW2 use in the ME and Pacific) but that's a minor point in the overall scheme of things.

The explosive action of the Shrap shell 'ejects' the balls/shot from the casing, which then falls to earth, often remaining intact. Many were subsequently souvenired, and thus it is probably the most commonly available variant of the 18pdr in collections because of that.

Mike C

[David Hardway]

Hmmmmmm i know these pics of the approx 10 Morris CDSW tractors to come to NZ there are remains of at least 5 still known to exist just not really enough to build a decent truck

Dave