British SAA for Vickers MGs

[Tom Tulloch-Marshall]

Can anybody offer advice on quantities of ammunition supplied for the Vickers, late 1916, how many rounds each, as follows -

# A "belt box filled with ammunition" (I assume the diarist means boxes containing loaded belts ready to fire)

# A "box" of SAA.

Could anybody also advise as to how much cooling water would be used by a Vickers being quite heavily used - say X gallons / Y rounds, and roughly what % of that water might be recovered as condensate.

Tom

[TonyE]

The standard belt box held a single belt of 250 rounds. The "box" is presumably the most commonly encountered boix that held 1,000 rounds, usually packed in ten round paper bundles or 50 round bandoleers. A couple of pictures are attached of WWI boxes.

I have the figures for water usage so will dig them out and post them if no-one else does.

Regards

TonyE

[Andrew Upton]

Could anybody also advise as to how much cooling water would be used by a Vickers being quite heavily used - say X gallons / Y rounds, and roughly what % of that water might be recovered as condensate.

Well, it varies a bit in official sources, but one given in Goldsmith's "Grand Old Lady" lists the following:

"Holds about 7 1/2 pints. Weight about 10 LB. Boils after 600 rapid. Evaporates 1 1/2 pints per 500."

So in theory a heavily used gun holding 7 1/2 pints in the jacket, from cold, could be boiled dry after firing around 2500-3000 rounds or so...

[TonyE]

Thanks Andrew, you beat me to it.

All sources seem to agree that it takes about 600 rounds to boil, one source saying "at rate of 200 rounds per minute"

The Vickers handbook, Pamphlet No.1 (1940 edition) states "The water in the barrel casing begins to boil when the gun has fired about 600 rounds in the case of .303 inch guns and about 250 rounds rapid in .5 inch guns: after this, if the firing is continued, the amount of water evaporated is about 1 1/2 pints for every two belts fired."

What I cannot find anywhere is how much water can be recovered from the condensate. I have looked in the handbook, TBSA 1929, Dolf's book and others but found nothing.

Regards

TonyE

[Tom Tulloch-Marshall]

Thanks - very helpful answers.

With regards to water recovery from condensate the answer is probably "very variable" (?) depending upon ambient temperature, how much water is in the recovery can and what temperature it is, whether the steam tube is pushed to the bottom of the tank etc etc etc. Does an average of 50% recovery sound like a reasonable guess ?

Next question. Say a Vickers was being heavily used (call it "continuous" barrage firing) over a period of some hours, what might you expect the average hourly ammunition expenditure to be - obviously taking into account belt changes, barrel changes, stopping to refill with water, occasional maintenance and general faffing-about. Forgetting the "movie" depiction of guns that just fire and fire and fire, what might a reasonable hourly ammunition expenditure be ?

Tom

[TonyE]

A good example under non combat conditions is the following.

When the Vickers was withdrawn from service in 1968 a final tribute to the gun was held at Strenshall Barracks in Yorkshire. A Vickers was selected at random and fired for seven days and nights non stop, consuming 5 million rounds of .303 inch ammo. Shot out barrels were changed every 1 to 1 1/2 hours and the two man crew swapped every thirty minutes.

That works out at 29,761 rounds per hour or 496 rounds per minute including all changes!

When the gun was returned to workshops and gauged, no wear was found on the working parts.

A more realistic figure is the crossing of the Rhine in August 1944. The machine gun section of the 1st Manchesters fired 338,000 rounds during the night. There are too many variables to be certain, but if it was eight guns firing for eight hours that would be just over 5,000 rounds per hour.

Another example is the barrage fired at High Wood on 24th August. Ten guns of the 100th MGC fired 900,750 rounds in twelve hours, about 7,500 rounds per hour. It needed two infantry companies as labour to bring the ammunition, water and spares forward.

Regards

TonyE

[Andrew Upton]

Another example is the barrage fired at High Wood on 24th August. Ten guns of the 100th MGC fired 900,750 rounds in twelve hours, about 7,500 rounds per hour.

I think your maths might be a little off there Tony - the quote given is "250 rounds short of one million were fired by ten guns", which would give 999,750 rounds fired, the even more impressive average of around 8300+ rounds per gun per hour. The best team of Sergeant P Dean, DCM, fired 120,000 rounds in that time, averaging 10,000 an hour, or over 160 rounds a minute (including all stoppages, breakages, barrel changes and water changes as required!).

[Andrew Upton]

With regards to water recovery from condensate the answer is probably "very variable" (?) depending upon ambient temperature, how much water is in the recovery can and what temperature it is, whether the steam tube is pushed to the bottom of the tank etc etc etc. Does an average of 50% recovery sound like a reasonable guess ?

Using the High Wood data again might help if someone can do the maths:

"at least four petrol tins of water besides all the water bottles of the Company and the urine tins from the neighbourhood were emptied into the guns for cooling purposes..."

Normal petrol tin = 2 gallons. Total = 8+ gallons. Now, what's the strength of an MGC Company at this time, though I fear the urine tin information is too general to be of help...?

[centurion]

At the other extreme cold was a problem and glycerine might be added up to 33% to stop water jackets freezing. This however did not stop oil getting thicker (congealing) in the cold and an increased rate of no one stoppages resulting. One former machine gun officer relates "It was a standing order for sentries to fire single shots or very short bursts throughout the night. This was the best way of keeping the barrel warm."

2 areas of questions

What, if any was the effect of glycerine when the gun heated up? - did it affect the point at which boiling started. Did it impact on evaporation

What was the effect on the oil of a very hot gun? I know from my time with aero engines that extreme heat can affect lubrication - did this apply to machine guns?

[Ron Clifton]

Using the High Wood data again might help if someone can do the maths:

"at least four petrol tins of water besides all the water bottles of the Company and the urine tins from the neighbourhood were emptied into the guns for cooling purposes..."

Normal petrol tin = 2 gallons. Total = 8+ gallons. Now, what's the strength of an MGC Company at this time, though I fear the urine tin information is too general to be of help...?

Hello Andrew

Establishment of a machine-gun company at the time was ten officers and 144 men, with sixteen Vickers m/guns. I don't have the rest of the quote to hand but my recollection is that the, er, recycled water was garnered from every other unit within available range.

Ron

[TonyE]

I think your maths might be a little off there Tony - the quote given is "250 rounds short of one million were fired by ten guns", which would give 999,750 rounds fired, the even more impressive average of around 8300+ rounds per gun per hour.

There is nothing wrong with my maths, Andrew, it is the quote I used that is wrong!

I picked the figures up from essentialsomme.com (http://www.essentialsomme.com/articles/british_machine_gun_tactics.htm) which quotes the 900,750 figure I used!

Their error, not mine.

Cheers

tonyE

[Andrew Upton]

Establishment of a machine-gun company at the time was ten officers and 144 men, with sixteen Vickers m/guns.

So with each man having a half-litre capacity water bottle, that gives about 17 gallons, so 25+ gallons of water with the petrol tins. That gives 200 pints alone, enough to fully top up one gun to 7 1/2 pints capacity over 26 times - and the urine tins still have to be factored in... Edited to correct my defective maths...

[Bombadier]

Basically, dissolving anything in water will raise the boiling point. The amount depends basically on the molecular weight of the solute and the concentration. It is too long since I did the chemistry which is needed to calculate this. It will also lower the freezing point. Nigel

[centurion]

Basically, dissolving anything in water will raise the boiling point. The amount depends basically on the molecular weight of the solute and the concentration. It is too long since I did the chemistry which is needed to calculate this. It will also lower the freezing point. Nigel

AFAIK Glycerine and water is not a solution and the way in which some of the hydrogen atoms in water become bonded to the hydro carbons in the glycerine it could lower the boiling point - hence my question

[Bombadier]

I think we must define accurately what we are discussing here. The boiling point of glycerine (glycerol) does decrease as it is dissolved in water. Conversely, the boiling point of the water must have increased. Attached table http://www.sy-kogyo....data/phase1.htm shows this effect at various pressures, 760 mm Hg being normal atmospheric pressure. If it was going to lower the boiling point, what would be the point of adding it to the water in the cooling jacket?

Nigel

[TonyE]

Presumably as anti-freeze if it lowers the freezing point.

Regards

TonyE

[Bombadier]

True. Anti freeze would, I suspect, be needed in winter so glycerol would serve a dual purpose.

Nigel

[Tom Tulloch-Marshall]

... Another example is the barrage fired at High Wood on 24th August. Ten guns of the 100th MGC fired 900,750 rounds in twelve hours, about 7,500 rounds per hour. ...

... the quote given is "250 rounds short of one million were fired by ten guns", which would give 999,750 rounds fired, the even more impressive average of around 8300+ rounds per gun per hour. The best team of Sergeant P Dean, DCM, fired 120,000 rounds in that time, averaging 10,000 an hour, or over 160 rounds a minute (including all stoppages, breakages, barrel changes and water changes as required!).

Er - Terry Norman, The Hell They Called High Wood, pp 197-8. - Guess which reported action prompted the original question

Terry Norman seems to have copied, almost point by point, from Weapons & War Machines by Hogg and Anderson (1976), and I have a suspicion that this "famous incident" may not be all it has been reported to be. Andrew, where does the report ref Sgt Dean come from ?

Any more reports of ammunition rates based on "test" conditions rather than reported battlefield events ?

Tom

[Bombadier]

http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/iechad/1925/iechad.1925.17.issue-9/ie50189a017/production/ie50189a017.fp.png_v03

hopefully this shows the freezing point table.

Nigel

[Tom Tulloch-Marshall]

For reasons which will become apparent shortly, I'm closing this thread. I'll pick it up in "Western Front", maybe Monday or Tuesday (I've finally managed to download last week's TNA photos).

If anybody has news ref Sgt Dean in the interim can they please pm me, or pick up on the new thread.

Tom