WWII War Diaries - Ammunition Identification from diary abbreviations.

[gartmoreheritagesociety]

Good Afternoon, I have been studying recently de-classified war diaries regarding 25 A.S.D. (Ammunition Sub Depot) and the ammunitions stored there. The 286 pages discuss the following ammuntion, and I was hoping someone might help me in deciphering what the abbreviated terms mean (perhaps also to send me links so I can read more about this). Many thanks, Paul Wilson

Generators Smoke No. 24 MKI

Ammunition categories ‘c’ and ‘cc’

B.L. 155mm H.E. Plugged

C.W. filled 'G' (obsolescent natures)

C.W. ammunition filled 'Y' (obsolescent natures)

QF 3.7 H.E.

B.L. 4.5 H.E. W/Top Exploders

Category E storage

Bombs “U” M.118 5in

Spigot Mortar 20lbs HE

Bombs M.L. 4.2 Mortar H.E. - S.A.A.

Bombs 5” U

Bombs 5” U filled G

Bombs 5” U filled G.1

Fuses 117

Ground 6lbs filled Y. 5.

Cartidges 40mm H.E.

Cartidges QF 40mm H.E.

Cartridges 18 pdr H.E. fuzed 117

Mines A/T (anti-tank?) with fuses

25 pdr H.E.

Bombs M.118

Mazak Fuzes

Regarding Ammunition / shells what is the meaning of ‘Central A in U store’?

S.I.O.O.laboratory

V.P. Patrols

W.E. Committee

D.D.W.S. (E).

7.2” shell

 

[tankbarrell]

BL is Breech Loading. This is just a term that by that time just meant a bag charge rather than a cartridge case.
QF is Quick Firing. This indicates a cartridge case is used.
HE is High Explosive.
Mazak is a type of pot metal that some fuzes were made from rather than brass.

 

[AMMOTECHXT]

Sorry if my answers are a little random. Others here may be able to better clarify some of the information.

CW filled G, Y etc means chemical weapons filled with G or Y mixtures. I think the letter refers to the mixture by proportions of its constituents. G and Y are codes that refer to the chemical. Similarly Bombs 5 Inch U filled G or G1 and 6 Lb ground bombs filled Y5. No doubt some of the mixtures were categorised by their persistency, i.e. whether thickened so that chemical fumes would be released for days or weeks after their deployment.

A/T stands for anti-tank as you suspected.

Central A in U store = Articles in Use store, such things as shell guages, preservative greases, clamps, conveyor gravity roller etc.

DDWS(E) means something along the lines of Directorate (or Director) for the Department of War Studies (Explosives).

c, cc and E, I believe all refer to ammunition storage categories, that system was changed before my time. All have mixing rules tied to them and the size (net explosive quantity) of each stack would be limited to prevent a total wipeout in the event of an explosion.

SIOO Laboratory = Senior Inspecting Ordnance Officer Laboratory. This is what I would have known as an Ammunition Process Building, where ammunition enters a building at one end, is worked on in the main part of the building, and is then sent out from the other end of the building. The SIOO is the figurehead.

Calibres: 3.7, 4.2, 4.5 and 7.2 all refer to the diameter of the ammunition in inches. 155 mm and 40 mm refers to the diameter of the ammunition in millimetres. Similarly 18 pr and 25 pr is another way of expressing the calibre of the ammunition for shells. The 20 Lb Spigot mortar bomb and 6 Lb Ground bomb most likely relate to the weight of an item of ammunition.

BL 4.5 HE W/Top exploders: A 4.5 inch diameter high explosive filled, breech-loading shell, fitted with explosive boosters in the top. The exploders contained a more sensitive explosive than the main filling of the shell and these acted as an intermediary between the fuze and main filling.

Please use the search facility to find out more about some of the specific items you mention. It might also be worth your while to view the downloads if you have sufficient access rights.

There is also a thread about smoke generators. The No 24 was a large one that emitted smoke for many minutes.

 

[TimG]

Generators Smoke No. 24 MKI - as explained

Ammunition categories ‘c’ and ‘cc’ - as explained

B.L. 155mm H.E. Plugged - These projectiles were issued un-fuzed and to protect the filling from water etc., they werer supplied with a plug (invariably metal) screwed into the fuze pocket.

C.W. filled 'G' (obsolescent natures) - Chemical Weapons - We had three natures of Chemical Weapons - B - Lachrymatory gases, G - choking and nose gases, Y - vesicant gases. These stores are all but obsolete and have presumably been/being replaced by newer designs.

C.W. ammunition filled 'Y' (obsolescent natures) - see above.

QF 3.7 H.E. - as explained

B.L. 4.5 H.E. W/Top Exploders - This has me puzzled as the description is stating the obvious.

Category E storage - as explained

Bombs “U” M.118 5in - This is the warhead for a 5" UP - Unrotated Projectile (Rocket) issued in Box M.118. See - https://www.bocn.co.uk/threads/box-m-118-mk-i-2-bombs-5-in-u-chem.106473/#post-330692

Spigot Mortar 20lbs HE - as explained

Bombs M.L. 4.2 Mortar H.E. - S.A.A. - Confusing, from what I recall, 3" mortar was an infantry weapon and 4.2" was an artillery weapon, it certainly wasn't S.A.A. - Small Arms Ammunition.

Bombs 5” U - Presumably as above but HE filled.

Bombs 5” U filled G - See above

Bombs 5” U filled G.1 - See above

Fuses 117 - Standard artillery fuze

Ground 6lbs filled Y. 5. - Chemical Weapon mine

Cartidges 40mm H.E.- 40mm Bofors ammunition.

Cartidges QF 40mm H.E. - Same as above

Cartridges 18 pdr H.E. fuzed 117 - I'm surprised this is not shown as obsolescent, by WWII the 18Pr had all but been replaced.

Mines A/T (anti-tank?) with fuses - as explained

25 pdr H.E. as explained

Bombs M.118 - As above

Mazak Fuzes - As explained. Without a Number it is hard to tell, but I suspect No. 119 fuzes.

Regarding Ammunition / shells what is the meaning of ‘Central A in U store’? - as explained

S.I.O.O.laboratory - To expand upon Ammotechxt's explanation the depot would have been staffed predominantly by members of the R.A.O.C. - Royal Army Ordnance Corp. A number of these would have been N.C.O. A.E.s - Ammunition Examiners (now Ammunition Technicians). All of whom were under the command of the S.I.O.O. a commissioned officer of the R.A.O.C.

V.P. Patrols - n/k

W.E. Committee - n/k

D.D.W.S. (E). - as explained

7.2” shell - as explained

TimG

 

[Snufkin]

For the 20lb spigot bomb (anti tank round for the 29mm Spigot Mortar, aka Blacker bombard), an image here:

https://www.bocn.co.uk/threads/blacker-bombard-29mm-he-20lb-bomb.86853/#post-233260

For the 6lb ground bomb:

https://www.bocn.co.uk/threads/ground-bomb-6lb-mki-ii.100834/#post-304190

As stated above, fillings B, G and Y were chemical warfare agents. The 6lb ground bomb filling Y5 was a mixture of sulphur mustard and monochlorobenzene.

The filling G1 was the Great War favourite, code CG, phosgene.

 

[gartmoreheritagesociety]

Sorry if my answers are a little random. Others here may be able to better clarify some of the information.

CW filled G, Y etc means chemical weapons filled with G or Y mixtures. I think the letter refers to the mixture by proportions of its constituents. G and Y are codes that refer to the chemical. Similarly Bombs 5 Inch U filled G or G1 and 6 Lb ground bombs filled Y5. No doubt some of the mixtures were categorised by their persistency, i.e. whether thickened so that chemical fumes would be released for days or weeks after their deployment.

A/T stands for anti-tank as you suspected.

Central A in U store = Articles in Use store, such things as shell guages, preservative greases, clamps, conveyor gravity roller etc.

DDWS(E) means something along the lines of Directorate (or Director) for the Department of War Studies (Explosives).

c, cc and E, I believe all refer to ammunition storage categories, that system was changed before my time. All have mixing rules tied to them and the size (net explosive quantity) of each stack would be limited to prevent a total wipeout in the event of an explosion.

SIOO Laboratory = Senior Inspecting Ordnance Officer Laboratory. This is what I would have known as an Ammunition Process Building, where ammunition enters a building at one end, is worked on in the main part of the building, and is then sent out from the other end of the building. The SIOO is the figurehead.

Calibres: 3.7, 4.2, 4.5 and 7.2 all refer to the diameter of the ammunition in inches. 155 mm and 40 mm refers to the diameter of the ammunition in millimetres. Similarly 18 pr and 25 pr is another way of expressing the calibre of the ammunition for shells. The 20 Lb Spigot mortar bomb and 6 Lb Ground bomb most likely relate to the weight of an item of ammunition.

BL 4.5 HE W/Top exploders: A 4.5 inch diameter high explosive filled, breech-loading shell, fitted with explosive boosters in the top. The exploders contained a more sensitive explosive than the main filling of the shell and these acted as an intermediary between the fuze and main filling.

Please use the search facility to find out more about some of the specific items you mention. It might also be worth your while to view the downloads if you have sufficient access rights.

There is also a thread about smoke generators. The No 24 was a large one that emitted smoke for many minutes.

Many many thanks for your answers and information. I'm not an ordnance expert, by any means, but the story I'm uncovering is quite bewildering! We're a tiny village in the middle of nowhere in Scotland, and to try to understand what went on here in WWII is quite staggering. From the recently declassified War Diaries, I obtained 3 weeks ago, I'm putting together an altogether completely forgotten chapter in our local history. I'd like to know how many A.S.D.'s ( Gartmore is 25 A.S.D.) there were in WWII. Again, many many thanks for your help. VERY much appreciated.

Paul Wilson

 

[gartmoreheritagesociety]

For the 20lb spigot bomb (anti tank round for the 29mm Spigot Mortar, aka Blacker bombard), an image here:

https://www.bocn.co.uk/threads/blacker-bombard-29mm-he-20lb-bomb.86853/#post-233260

For the 6lb ground bomb:

https://www.bocn.co.uk/threads/ground-bomb-6lb-mki-ii.100834/#post-304190

As stated above, fillings B, G and Y were chemical warfare agents. The 6lb ground bomb filling Y5 was a mixture of sulphur mustard and monochlorobenzene.

The filling G1 was the Great War favourite, code CG, phosgene.

Thanks so much for your reply. I downlaoded pdf's from MLRS to help me, and I'm working my way through them - I'll use your images to help me, aprticularly regarding the chemical warfare aspect. In our area we had 6 X 'C.W. Decontamination Units'.

 

[gartmoreheritagesociety]

Good Morning Gentlemen. I was recently enquiring about Mazak Fuzes, and to understand them more I thought it might be useful to attach the War Diary record for your perusal to enable you to comment about what type of fuze it is.

 

[AMMOTECHXT]

Mazak is a white metal alloy, very light and strong, provided it is not subjected to moisture, particularly salt water. From memory I believe it was a mixture of Magnesium, Aluminium and Zinc. The tails of 2 Inch mortar bombs, magazine caps (i.e. the screwed-on closures on the bottom of some artillery fuzes) were often made of Mazak early in WW2. Once subjected to water, Mazak turns a grey colour and becomes flaky and brittle, literally crumbling away. From your post the fuzes of 40 mm shell were also made of Mazak. I'm guessing many other ammunition items were too.

The Mazak tails of 2 Inch mortar bombs were subsequently replaced with steel. Later versions of fuzes were fitted with brass magazine caps. The Number 151 Fuze used with 4.2 Inch HE mortar bombs was also made largely of a white metal, possibly Mazak, that was prone to crumbling once dampened.

I forget the model of fuze now (an L series fuze, rather than an earlier numbered fuze) but I think it was made of Aluminium and Zinc and was fitted to 105 mm Illuminating shells that I helped to look after in Belize in 1988. It was found that they had been unpackaged but not fired, then replaced into their thick cardboard inner containers. Whatever moisture was in the atmosphere when they were replaced got to work and when I saw them the fuzes were falling to bits. Not good in conditions of high humidity and temperature.

 

[gartmoreheritagesociety]

Mazak is a white metal alloy, very light and strong, provided it is not subjected to moisture, particularly salt water. From memory I believe it was a mixture of Magnesium, Aluminium and Zinc. The tails of 2 Inch mortar bombs, magazine caps (i.e. the screwed-on closures on the bottom of some artillery fuzes) were often made of Mazak early in WW2. Once subjected to water, Mazak turns a grey colour and becomes flaky and brittle, literally crumbling away. From your post the fuzes of 40 mm shell were also made of Mazak. I'm guessing many other ammunition items were too.

The Mazak tails of 2 Inch mortar bombs were subsequently replaced with steel. Later versions of fuzes were fitted with brass magazine caps. The Number 151 Fuze used with 4.2 Inch HE mortar bombs was also made largely of a white metal, possibly Mazak, that was prone to crumbling once dampened.

I forget the model of fuze now (an L series fuze, rather than an earlier numbered fuze) but I think it was made of Aluminium and Zinc and was fitted to 105 mm Illuminating shells that I helped to look after in Belize in 1988. It was found that they had been unpackaged but not fired, then replaced into their thick cardboard inner containers. Whatever moisture was in the atmosphere when they were replaced got to work and when I saw them the fuzes were falling to bits. Not good in conditions of high humidity and temperature.

Brilliant.... thanks so much. There'll be more questions coming (not many!!).