Talk:ML 3-inch mortar

Mark

Many, perhaps most, internet sources incorrectly identify the early WWII ML 3-inch as Mark I. It's seems like they assume the short range OML mortar was Mark I and and the long range Mark II. The Stokes was Mark I. The Ordnance ML 3-inch was Mark II. The range was mostly improved with the exisiting MkII mortar by just improving the propellant. But later in the war the mortar was improved further, but remained the Mark II. It's important that the 'Marks' for this mortar are understood to be generational, not incremental. So the early war (1939-1942) Mk II had a range of 1600 yards, the mid-late war (1942-45) Mk II had a range of 2800 yards. I have a copy of the British 1939 training manual for the 3-inch mortar, and it's very clearly called the Mark II with a range of 1600 yards. I also have the updated 1943 training manual, and it's still called the Mark II with a range of 2800 yards. Hope this clears it up. Mod Reasearch. — Preceding unsigned comment added by 174.59.33.104 (talk) 23:15, 22 September 2012 (UTC)

Calibre

As I have access to one of the original handbooks on the 3-Inch MkII I thought I'd better throw it in as a source. The Handbook Ordnance, M.L 3-Inch Mortar, MarkII, on Mounting, 3-inch Mortar, Mark I Land Service 1937 with three reprints with amendments, latest 1942 (is the version I have acces to). On page 14 it states: Particulars Material Steel Weight (approximate) complete 1qr. 14lb. Length without breech piece 48 inches. Length with breech piece 51.1 inches. Bore-

Length from muzzle to front of striker stud 45.25 inches.
Diameter  3.209 inches
Firing mechanism  percussion.

Given it specifies 3.209 inches I have amedned the page thus.

Unfortunately I couldn't get to our actual 3 Inch to confirm with a set of calipers because the Armourers from Military Heraldry and Technology advised me it is all packed away in storage. Therefore I've relied entirely upon printed original source material.

Cheers Curator Official Records Australian War Memorial

---

— Preceding unsigned comment added by 203.6.145.242 (talk) 03:31, 5 December 2012 (UTC)

The reason the British called it a 3-inch mortar is the same reason I call my car 3.2 liter rather than the more accurate 3,198cc It's just rounded to the nearest whole number.

The Stokes was also 3.2 inches.174.59.33.104 (talk) 21:59, 21 September 2012 (UTC)

---

I'm not going to change the article, as I see that someone already has, and this has been reverted by someone measuring a mortar in the NZ Army museum. However I would pipe up on this mortar being 81mm during WWII, and certainly in the Korean War, both of which are well prior to the introduction of the L16 81mm Mortar in 1965 - but I cannot say if this is the original mortar or the Mark II barrel one. This is a nitpicking area but I'd like to provide a quote here for people to chew on, and it's a bit of an essay:

Researchers (Charles Markuss, Kenneth Katz and Shaun Carter) developing the board game Advanced Squad Leader described their findings in ASL Journal Issue Seven in 2006. It was noticed that the new book "Infantry Mortars of World War II" from the New Vanguard series by Osprey Publishing described the British 3-inch mortar as being 3.2 inches or 81mm. Previous standard sources for the game had given 3 inches or 76.2mm. Later consultation of User Manuals, measurement of a 3-inch mortar at the Small Arms School Corps museum in Warminster, and an interview with a retired Infantry Major John Oldfield who had used the weapon in Korea all indicated the calibre as 3.21 inches or 81mm - which surprised everyone.

During WWII the British provided a special, more pointed, firing pin to allow the mortar to fire captured Italian and German 81mm mortar ammunition.

Now, me reading this makes me think the mortar was 81mm - but exactly when this was the case I cannot say - it may be that the British changed during WWII to 81mm, which would have been typical in trying to fit in with US artillery logistics, as well as being able to use German, Italian and French ammunition. But then if the British started with a genuine 3-inch mortar what happened to their ammo stocks from prior to the changeover? Was the weapon 81mm all along? Did the British/Commonwealth forces have a mixed stock of mortars and ammunition (maybe explaining the findings in New Zealand)? Some corroboration on use of captured ammo would be useful.

Does this constitute original research? It isn't by me - the 81mm calibre is published in the above-mentioned book (at least that's what the Journal says) and obviously that figure is repeated with explanation in the Journal. This is a serious wargame, and they are planning to issue erraticised counters at the time of writing. Discuss Stevebritgimp 23:21, 19 October 2007 (UTC)

Just a quick note. The British 3" mortar was always 81mm in calibre. Almost all WW2 medium mortars were of the same calibre because they were copies, licensed or not, of the 1930's French Brandt design. In general they could all fire each others ammunition, though as some countries used greater propellent charges this could be hazardous. As you mention the UK pattern needed a different firing pin due to a diferent The exception was the USSR with its 82mm mortar, which could fire 81mm bombs, but not vice-versa.

I have no idea why the British refer to the weapon as "3 inch" rather than 3.2"/81mm; it may be related to its predecessor, the 3 inch Stokes mortar. It appears that most sources simply assume the calibre to be 76mm because of the name, without verifying, and then other are using this same research.

As for someone measuring a mortar, this may have been an earlier 3" Stokes pattern, which was 3" calibre. —Preceding unsigned comment added by 83.71.231.1 (talk) 22:57, 21 March 2008 (UTC)

Yes, it's an interesting one - the Stokes mortar was a trench mortar going back to WWI, and I would imagine the WWII era weapon as a mortar would be more flexible in what ammunition it used, say compared to a rifled artillery piece which would need very specific ammunition to work. The Brandt mortar is the gold standard of its day (although on wiki, at least a couple of months ago if you typed in 81mm Mortar you'd end up with the US weapon, and the French weapon didn't even have its own page - for shame!) But I don't know the practicalities of how these weapons worked. A previous change to the calibre on the page resulted in a reversion. I think the 81mm calibre for the WWII era weapon may be gaining ground, but this is arcane militaria stuff, even to me. More opinions and facts may be needed to make this one stick Stevebritgimp (talk) 22:38, 22 March 2008 (UTC)

Regarding the name of the weapon, why are we assuming that it was (or should be named) for the caliber of the tube itself? Given the nature of drop-fired mortars, in that the bomb has to slide freely down the barrel, isn't it possible that the bombs themselves are roughly 3 inches in size and the weapon is named after its projectile? Perhaps some ordnance collector can measure one of them for us. Just a thought. As to the whole "rounding down" thing, this would make more sense if the British didn't also make use of a 4.2-inch mortar during the war.--172.190.184.149 (talk) 21:58, 24 January 2013 (UTC)

Recent deletion of description of calibre

Referring to this edit here:

[1]

The single most useful content in this article has been removed as 'uncited' presumably because there was a citation tag in the paragraph, even though none of the other paragraphs have any sources, and have not been deleted (might it be better to delete the whole article, just to be on the safe side?), and also the citation refers to materials 'not' including the specs of the mortar - i.e. a citation would somehow have to demonstrate absence, rather than presence, of information, which might be hard if that source was large, and indeed how many sources lacking this information would we have to provide? The paragraph did contain mention of the two infantry manuals, which if anything is a kind of citation (although I won't pretend to know what the proper wikipedia policy on that is). Is there a way this information can be returned to the article without it being taken out again? This is especially important considering the constant reverting we had on the calibre of the weapon before this information came to light. Personally if the infantry manuals were cited better that might help. Cheers. Stevebritgimp (talk) 20:04, 3 March 2011 (UTC)

Further to this - I'm assuming the 1951 pamphlet is this: INFANTRY TRAINING Volume II. Infantry Heavy Weapons Pamphlet No.21 THE 3-INCH MORTAR 1951. WO8594. I'm having difficulty finding a more detailed description of the 1963 manual anywhere. There is also INFANTRY TRAINING Volume II. Infantry Heavy Weapons Pamphlet No.2A THE 81mm MORTAR ( AUSTRALIA). 1965. ( 7610-66-021-1656), but I'm assuming that is the later 81mm model. I have not viewed these manuals, these are just traces I've found on google. I'm assuming the person who originally added the paragraph has seen them. Maybe could do with knowing that yeigh or neigh. Stevebritgimp (talk) 20:32, 3 March 2011 (UTC)