Talk:BL 5.5-inch medium gun

Alternate specs found
GENERAL PARTICULARS:

Calibre: 5.5 inches (140 mm) Weight: 5850 kg (5 3/4 tons approx.) Shell weight: 36.3 kg (80 lbs) high explosive. Smoke and illuminating also fired Rate of fire: 3 rpm Muzzle velocity: 510 metres/second (1673 f/s) with Charge 4 Number of charges: 4 Maximum range: 16,400 metres (17935 yards) Elevation: 45° Traverse: 30° right and left Detachment: 10

GraemeLeggett 14:32, 4 Jun 2005 (UTC)

Korea
Korean service has just been removed. Can we source the actual units that served with this gun? 74 Medium Battery (Battleaxe) from Hong Kong was an obvious one, probably the most famous.

Some photos of 5.5s in high angle: http://www.riv.co.nz/rnza/pg/kor/awkor1.htm

Andy Dingley (talk) 23:20, 9 June 2015 (UTC)

Andy it appears that you are right in that according to this web page the 74th Medium Battery of the 32nd Medium Regiment Royal Artillery, which were equipped with 5.5s, served in Korea from February 1953 until some indeterminate point in the future. However I have as of yet been unable to find if any other unit deployed to Korea equipped with 5.5s other than the 98th Medium Battery which apparently which deployed to Korea shortly after the armistice was signed.

http://british-army-units1945on.co.uk/royal-artillery/32nd-regiment-ra.html — Preceding unsigned comment added by Mrniceguy101 (talk • contribs) 15:52, 10 June 2015 (UTC)

Huh?


In the 'Description' section, para 2, there is this: 'During World War II the PL Locks and AC Slide Boxes used with 0.5 inch tubes were replaced by PK Locks and Y Slide Boxes using 0.303&nbsp'. I'm sure it is all very interesting, but what is a 'PL Lock' and a 'Slide Box' and so on? I have no idea and I'm sure I won't be the only reader of this article who is equally baffled.

RASAM (talk) 14:08, 29 September 2016 (UTC)


 * Huh indeed! I have added a tag. I have no idea what it means and I am no newcomer to military hardware. An extreme use of jargon imo. Irondome (talk) 14:36, 29 September 2016 (UTC)


 * Artillery of this size (over 105mm) would be "BL" (Breech Loading) rather than "QF" (Quick Firing) - i.e. bagged charges rather than a one-piece brass case. So there also needs to be an obturator in the breech block to seal it and a firing tube placed separately in the breech to fire it. The breech block itself would be a interrupted screw breech, rather than sliding.
 * In the middle of this breech block is a '"lock", the thing that holds and fires the firing / primer / igniter tube. This lock both closes the cover enclosing the tube and also controls the firing pin (or electrical firing) for the primer tube. The lock isn't mounted directly on the breech though, but on the 'slide box' (rectangular thing beneath) which allows the lock to move so that it can't be loaded until the main breech is closed. The lock and slide box are effectively a rifle-calibre breech all of their own.
 * The piece is fired through an operating handle on the lock, pulled by a lanyard. The same handle also opened and closed the lock.
 * At the outbreak of WWII, all [sic] of the BL artillery used the same 0.5 inch diameter tubes, and the same lock and slide box, the PL lock and the AC slide box. They weren't a 5.5-specific component. "Tube, Vent, Percussion Mk 6 (0.5-inch)" was quite an old design and so it was replaced by the smaller calibre "Tube, Percussion Mk 3 (0.303-inch)". This required a corresponding new design of PK lock and Y slide box. The operation was slightly different too, in that the lock was now cocked by pulling the lanyard to fire the piece, rather than during loading. The handle became much smaller, enough to recognise in photos. The large handle can be seen in WWI and in some early desert campaign WWII photos, but most WWII footage will be the later PK lock with the small handle. Andy Dingley (talk) 14:49, 29 September 2016 (UTC)
 * Tubes and primers for ammunition


 * Thanks for the heroic attempt to simplify things Andy! I have attempted to clarify in a few words your excellent explanation. Simon. Irondome (talk) 15:37, 29 September 2016 (UTC)

surviving examples
There is also on in Newhaven Fort, Sussex UK 2A02:C7F:A108:5600:64B2:3432:803B:B2EC (talk) 15:51, 9 September 2021 (UTC)