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Nice 2 Inch British Mortar Shell Any info is appreciated.
- Thread starter Mikebiker
- Start date
Agreed. The embossed cross on the nose is a night identification feature for 2Inch HE.
Very nice find. Looking at the markings it's not Canadian. As for the nose cap never seen this mentioned in any training pamphlets or technicians books.
Filled Baratol 20/80 By BO/C - Defence Industries Ltd., Bouchard
I’m sure that red paint on the tail is of significance, but can’t remember why.
I don’t know the cartridge cap maker
No. 151 Mk I fuze made by PC/C - Pressure Castings of Canada Ltd.
Filled by Sc/C - General Engineering Co., Ltd. Scarborough, Canada.
TimG
I’m sure that red paint on the tail is of significance, but can’t remember why.
I don’t know the cartridge cap maker
No. 151 Mk I fuze made by PC/C - Pressure Castings of Canada Ltd.
Filled by Sc/C - General Engineering Co., Ltd. Scarborough, Canada.
TimG
I believe that it was remarked on in the relevant Part of Pamphlet 15 in Ammo & Explosives Regulations (A & ER) Volume 3. In 1989 I was tasked to a 2 Inch mortar bomb and therefore felt obliged to research all, so that I might at least look as though I knew what I was talking about. There is no mention or diagram of the embossed cross in the copy of DWS Notes that I have. Around ten years earlier I fired some Smoke and Illuminating bombs but by ten years later had forgotten most of what I knew, apart from dismantling some illuminating bombs in Belize in 1988. I guess the problem for me was that around the time I joined the army, 2 Inch HE was banned for issue and use due to accidents where soldiers were injured or killed and I therefore never saw one (or for that matter any other 2 Inch bombs) in an Ammo Process Building.
It would interesting to know how the accidents occurred during firing, was it dodgy bombs or firing procedure. I know that the early two inch with out the safety pin on the 151 fuzes if Jarred or dropped, released the shutter holding the ce pellet in line with the striker so when fired the bomb went off in the bore. This was rectified after accidents with airborne drops so I believe.
Having refered to a précis on the 2" mortar the markings of the example shown appear to conform with what was expected for UK manufactured rounds.
The painted vane identifies the tail as a Mk. II tail made of Mazak. Early types had a letter "Z" stamped on one vane, blob of red paint on the other side of vane. Later types had "No. 2" stamped on one vane. Other side painted red.
The problem with the Mk. I tails (Aluminium) was they could only be used the the 47 grain Mk. II cartridge as with 47gr Mk. I, 50gr, 55gr, etc., fracturing was liable to occur on firing.
TimG
The painted vane identifies the tail as a Mk. II tail made of Mazak. Early types had a letter "Z" stamped on one vane, blob of red paint on the other side of vane. Later types had "No. 2" stamped on one vane. Other side painted red.
The problem with the Mk. I tails (Aluminium) was they could only be used the the 47 grain Mk. II cartridge as with 47gr Mk. I, 50gr, 55gr, etc., fracturing was liable to occur on firing.
TimG
My WW2 DWS notes, printed in September 1943, give the following info about tails for the 2 Inch:
`Bomb ML HE 2-Inch Mortar ....... The tail unit is of die-cast aluminium or Mazak alloy formed with six vanes; recessed at the bottom to accommodate the cartridge and is screw-threaded externally to take the cartridge retaining cap. There are 18 holes to distribute the gas pressure evenly around the bomb. The top is screw-threaded to take the spigot of the bomb to which it is secured by a grub screw. The production of bombs with steel tails is to be expected.' It goes on to say pretty much what Tim has said: `Cartridges for the 2-inch mortar are charged with ballistite on account of the low pressure developed in the bore. There are two weights of charge; the 47-grain charge is primarily for use with aluminium tails and the 55-grain charge is used with the heavier Mazak or steel tails.' 47-grain cartridges were stencilled in black and 55-grain cartridges were stencilled in red. Maker and Mark were stencilled on the side; date and lot number on the top of the cartridge. Mark I and Mark II cartridges existed for each charge weight `which correspond in structure to the Mark VIII and Mark IX 95-grain cartridge for the 3-Inch mortar.' `The priming of G20 is confined in a coppered tube in the Mk I cartridge and in a celluloid cup in Mk II. The shapes of anvil and cap chamber differ in the two marks.'
An entire page is given over to information about tail units: `There have been two distinct tail units, one made of aluminium-silicon alloy and the other of Mazak (a zinc alloy). The containers have 18 flash holes in three tiers of six. The aluminium tails were found to be liable to fracture and have been superceded by the Mazak tail. The Mazak tail is liable to fracture at extreme low temperature and is being replaced by bombs with steel tails.
The approved association of cartridges and tails was originally the 47-grain Mk I cartridge for aluminium-silicon tails and the 55-grain Mk I cartridge for Mazak tails. When the liability of aluminium tails to fracture was noticed, ACI 862/1941 was issued explaining the association of tails and cartridges and ordering a sorting of mortar bombs by tail material.
It was later recognised that the aluminium tails were satisfactory when fired with a 47-grain Mk II cartridge, and instructions were issued for packages containing bombs of this assembly to be marked "Mk II Cartridges." Instructions were issued in ACI 1840/1941 for aluminium tails fitted with Mk I 47-grain cartridges to be drilled with a fourth tier of flash holes. Packages of these bombs were to be marked "HC." Extracts from the instructions on the conversion of 2-inch mortar bomb tails appears as Appendix I.
Details of the approved cartridge for various bombs and tail units are given in para 20, page 23.
Cartridge retaining caps must be screwed tightly home before firing, otherwise a misfire may result due to insufficient protrusion of striker. All caps should on inspection be found rigidly attached by RD cement.'
An extract from ACI 862/1941 gave the info that bombs with fractured aluminium tails were liable to fall short. To help sort the types of tail unit: `All bombs filled before September 1940 are of the aluminium alloy type.
For info, ACI means Army Council Instruction; I believe that RD means Research Department, ie a government-funded facility. I don't know the meaning of `HC'.
The smoke bomb tail unit and cartridge retaining cap were identical to those of the HE bomb.
The Mk I smoke bomb used in the 2-inch bomb thrower (AFV use) was fitted with an 18-grain ballistite cartridge or the 18-grain Hercules 81 mm powder cartridge.
`Boxes of 2-inch mortar bombs fitted with steel tails will be marked "steel tails" in 1/2-inch lettering ...' There was a later, handwritten amendment to say that the "steel tails" marking would not apply to containers packed with Signal and Illuminating bombs. A TAL (Technical Ammunition Letter) issued later limited this to just Signal bombs. These were the single star red, single star green, multi star red, multi star green and multi star red and green.
This is incomplete. I will add more later.
`Bomb ML HE 2-Inch Mortar ....... The tail unit is of die-cast aluminium or Mazak alloy formed with six vanes; recessed at the bottom to accommodate the cartridge and is screw-threaded externally to take the cartridge retaining cap. There are 18 holes to distribute the gas pressure evenly around the bomb. The top is screw-threaded to take the spigot of the bomb to which it is secured by a grub screw. The production of bombs with steel tails is to be expected.' It goes on to say pretty much what Tim has said: `Cartridges for the 2-inch mortar are charged with ballistite on account of the low pressure developed in the bore. There are two weights of charge; the 47-grain charge is primarily for use with aluminium tails and the 55-grain charge is used with the heavier Mazak or steel tails.' 47-grain cartridges were stencilled in black and 55-grain cartridges were stencilled in red. Maker and Mark were stencilled on the side; date and lot number on the top of the cartridge. Mark I and Mark II cartridges existed for each charge weight `which correspond in structure to the Mark VIII and Mark IX 95-grain cartridge for the 3-Inch mortar.' `The priming of G20 is confined in a coppered tube in the Mk I cartridge and in a celluloid cup in Mk II. The shapes of anvil and cap chamber differ in the two marks.'
An entire page is given over to information about tail units: `There have been two distinct tail units, one made of aluminium-silicon alloy and the other of Mazak (a zinc alloy). The containers have 18 flash holes in three tiers of six. The aluminium tails were found to be liable to fracture and have been superceded by the Mazak tail. The Mazak tail is liable to fracture at extreme low temperature and is being replaced by bombs with steel tails.
The approved association of cartridges and tails was originally the 47-grain Mk I cartridge for aluminium-silicon tails and the 55-grain Mk I cartridge for Mazak tails. When the liability of aluminium tails to fracture was noticed, ACI 862/1941 was issued explaining the association of tails and cartridges and ordering a sorting of mortar bombs by tail material.
It was later recognised that the aluminium tails were satisfactory when fired with a 47-grain Mk II cartridge, and instructions were issued for packages containing bombs of this assembly to be marked "Mk II Cartridges." Instructions were issued in ACI 1840/1941 for aluminium tails fitted with Mk I 47-grain cartridges to be drilled with a fourth tier of flash holes. Packages of these bombs were to be marked "HC." Extracts from the instructions on the conversion of 2-inch mortar bomb tails appears as Appendix I.
Details of the approved cartridge for various bombs and tail units are given in para 20, page 23.
Cartridge retaining caps must be screwed tightly home before firing, otherwise a misfire may result due to insufficient protrusion of striker. All caps should on inspection be found rigidly attached by RD cement.'
An extract from ACI 862/1941 gave the info that bombs with fractured aluminium tails were liable to fall short. To help sort the types of tail unit: `All bombs filled before September 1940 are of the aluminium alloy type.
For info, ACI means Army Council Instruction; I believe that RD means Research Department, ie a government-funded facility. I don't know the meaning of `HC'.
The smoke bomb tail unit and cartridge retaining cap were identical to those of the HE bomb.
The Mk I smoke bomb used in the 2-inch bomb thrower (AFV use) was fitted with an 18-grain ballistite cartridge or the 18-grain Hercules 81 mm powder cartridge.
`Boxes of 2-inch mortar bombs fitted with steel tails will be marked "steel tails" in 1/2-inch lettering ...' There was a later, handwritten amendment to say that the "steel tails" marking would not apply to containers packed with Signal and Illuminating bombs. A TAL (Technical Ammunition Letter) issued later limited this to just Signal bombs. These were the single star red, single star green, multi star red, multi star green and multi star red and green.
This is incomplete. I will add more later.
It seems we all have the same information. Be intrested to see later notes as to why 2" HE bombs were stopped being used later on, post war I was told by a veteran armourer that we sold off our entire stocks of HE rounds to Australia post war, and bought them back because we needed them for the Aden crisis. The earliest Steel tail fin I have is a No:4 funny enough dated 10/43.
Analysing the Mk 1&2 55 and 47 grain balistite cartridges which are filled with the same amount of primary and secondary powder ie G20 black powder and balistite, it seems that the Mk 1 design with the central tube is similar to a hot primer in that it ignites the balistite off quicker as the balistite surrounds all round the tube than the gradual burn with the Mk 2 layout of the balistite being above the G20 black powder. That small difference can give the same performance but less stress on the tail fins. There was the 73grn cartridge for the rare signal success mortar round a parachute illum red to green fitted with steel tail, needed the hight to show the multi burn of the flares..
Analysing the Mk 1&2 55 and 47 grain balistite cartridges which are filled with the same amount of primary and secondary powder ie G20 black powder and balistite, it seems that the Mk 1 design with the central tube is similar to a hot primer in that it ignites the balistite off quicker as the balistite surrounds all round the tube than the gradual burn with the Mk 2 layout of the balistite being above the G20 black powder. That small difference can give the same performance but less stress on the tail fins. There was the 73grn cartridge for the rare signal success mortar round a parachute illum red to green fitted with steel tail, needed the hight to show the multi burn of the flares..
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During my time in the RAF (Airfield Construction Branch)I served in Aden,while at an "up country"base near the Yemen border 2"mortars were in frequent use,mainly paraflares,I managed to get a parachute (I beat an Arab guard in a footrace to get to it before he did),when a mortar was fired at night it was advisable to look up and define its trajectory,the flare drifted down slowly but the case on the other hand had nothing to slow it down,luckily there were no casualties,many flares landed within the confines of the camp as did some of the empty cases,
The parachute I managed to get my hands on unfortunately disappeared when my mum moved house,
Don,
The parachute I managed to get my hands on unfortunately disappeared when my mum moved house,
Don,
To continue with my last post (we had a visitor): From `An extract from ACI 862/1941 gave the info that bombs with fractured aluminium tails were liable to fall short. To help sort the types of tail unit: `All bombs filled before September 1940 are of the aluminium alloy type.' The ACI continues: `Bombs fitted with zinc alloy (Mazak) tails are marked with a "Z" stamped on one fin. In addition, a streak or blob of red paint should be found on one fin of the Mazak tail. It is possible that a few lots have been received without the red marking on the tail. Identification in each case will therefore be made by the "Z" stamp.'
There is also an extract from ACI 1830/1941: `The sorting of tails as laid down by ACI 862/41 will be carried out for both HE and Smoke bombs.
Conversion of aluminium tails to prevent fractures. - The conversion applies only to bombs assembled with Mk I cartridges. It has been found that liability to fracture of aluminium tails can be prevented by drilling a fourth tier of holes in the bomb tail. Mazak tails will not be converted.
Marking. - When aluminium tails have been converted, the packages will be identified by the letters "HC" (as Tim says: Holes Converted) stencilled in 2-inch letters on the package.'
`Specification for the method of conversion was for a fourth tier of holes to be drilled above the existing three tiers at the bomb end: the holes to be 0.2 inch diameter and 0.4 inch centre to centre from the third tier; cartridges to be removed before drilling and inside of the hole to be cleaned after drilling.'
There is also an extract from ACI 1830/1941: `The sorting of tails as laid down by ACI 862/41 will be carried out for both HE and Smoke bombs.
Conversion of aluminium tails to prevent fractures. - The conversion applies only to bombs assembled with Mk I cartridges. It has been found that liability to fracture of aluminium tails can be prevented by drilling a fourth tier of holes in the bomb tail. Mazak tails will not be converted.
Marking. - When aluminium tails have been converted, the packages will be identified by the letters "HC" (as Tim says: Holes Converted) stencilled in 2-inch letters on the package.'
`Specification for the method of conversion was for a fourth tier of holes to be drilled above the existing three tiers at the bomb end: the holes to be 0.2 inch diameter and 0.4 inch centre to centre from the third tier; cartridges to be removed before drilling and inside of the hole to be cleaned after drilling.'
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There was a handling / use constraint whereby bombs were not to be fired through overhanging tree branches if I remember correctly. Sounds like common sense really. Maybe someone forgot!!!
The following information is from a November 1945 publication, which rounds up all the wartime 2" mortar varieties of bombs, cartridges and tails.
This remained extant until 1954, when two amendments were produced, before the publication was superseded and produced in the Loxonbar version, where much of the information was not included because it was no longer relevant to technical staff.
CARTRIDGES TAIL UNITS (NOTE. this is supposed to be CARTRIDGES and TAIL UNITS as a table but I cannot get it to work)
47 gr Ballistite Mk 1 24 hole aluminium tails. Without the extra holes the tails will fracture on firing.
47 gr Ballistite Mk 2 18 hole aluminium tails. No fracturing should occur on firing
47 gr. 81mm. Powder Mk 1 (smokeless, N.A production) Mazak or steel tails
55 gr Ballistite Mk 1 Mazak or steel tails. A small %tage of mazak tails may fracture on firing, but
drilling extra holes not required.
55 gr Ballistite Mk 2 Mazak or steel tails. No fracturing of mazak tails should occur on firing.
50 gr Ballistite (smokeless) Mk 1 Mazak or steel tails. NOTE Mazak was deleted by Amendment 1 in 1954.
52 gr. 81 mm. Powder Mk 1 (North American production) Mazak or steel tails.
In addition to the normal package markings of the time, here are some special markings.
'HC' has already been mentioned.
The words 'ALUMINIUM TAILS' on boxes indicates that the aluminium tails in the package are not suitable for conversion to long range firing.
The letters "LR" indicate the presence of 55 gr or 50 gr Ballistite cartridges for long range firing. In addition, the spring catches, hinges and handle hinges are painted blue and a daub or blue band is painted on each cylinder of the bomb carriers.
A large quantity of boxes produced in North America were painted service green instead of light green. To indicate the presence of smoke ammunition, while obviating the necessity of re-painting the boxes, 2 inch light green bands were painted around the ends and across the top and bottom of each end.
A 1 inch letter 'X' in a circle in red, with an EXMND date means that the bomb fuzes have been X rayed and are safe for use.
I have seen the windshield caps in service, but have never heard of it being used to differentiate fuzes for use with HE only. It is more likely to be a strengthening feature to allow you to fire in driving rain or through thin vegetation. The only other bomb to use fuzes in the 151/161 series is the Bomb 2" Mor Bomb Thrower Bursting Mk 3 filled White Phosphorous. These disappeared in the 1950s as Grenade No 80 WP, fired by Fuze Electric F 103 became the AFV screening smoke of choice. The Bomb Mor 2" Practice HE also has a removable cap, but with a big nut head in the middle.
QUOTE "It has been found that premature bursts of 2" mortar bombs fuzed No 151 have have been caused by the use of ammunition which had made an abnormally heavy landing when dropped from aircraft during exercise. Such a landing would occur from complete failure of the parachute to open or partial opening only of the canopy with the resultant failure to check appreciably the rate of descent of the attached container". This led to the modification of the Fuze 151 and the introduction of Fuze 161.
MARKINGS OF CARTRIDGES (From Amdt 1 of 1954 this applied to Mk 1 only).
Until around the end of 1944 the only markings on the cartridge case, were Makers monogram/initials and Mark.
Then this: CARTRIDGE COLOUR OF CASE PAPER COLOUR OF STENCILLING (this should be a three heading table).
47 gr Ballistite Buff Black
50 gr Ballistite Buff Red
55 gr Ballistite Buff Red
18 gr Ballistite or Hercules Green Black
17 gr Ballistite or Hercules Green Black
42 gr G20 Green Black
73 gr Ballistite Green Red (for use with SIGNAL SUCCESS to gain sufficient height for suitable signal and burn duration).
Since the end of 1944 full details of cartridges are printed along the length in ONE EIGHTH OF AN INCH LETTERS as follows:
The word SMOKELESS where applicable.
2 in ML MORTAR or 2 in BOMB THROWER as applicable (the latter obviously no longer applicable).
"SIGNAL SUCCESS" as applicable (no longer applicable)
The weight and nature of the charge.
Mark of cartridge.
Manufacturer's initials or trade mark.
In an earlier post I mentioned that mazak tails may suffer from what is known as 'mazak poisoning' and that it is possible to detect this because the tail appears to have surface lines like crazy paving. There may also be a whitish powder present. As I said before, such tails can be crushed in the hand leaving part of the central tube.
The cause of this may be contact with some adhesives, but the main cause is damp due to repeated temperature changes, accompanied by high humidity in tropical climates. I encountered this in an extinct ammunition sub depot in Africa in the early 1960s. We had to replace all stocks of mazak tails with steel tails.
This remained extant until 1954, when two amendments were produced, before the publication was superseded and produced in the Loxonbar version, where much of the information was not included because it was no longer relevant to technical staff.
CARTRIDGES TAIL UNITS (NOTE. this is supposed to be CARTRIDGES and TAIL UNITS as a table but I cannot get it to work)
47 gr Ballistite Mk 1 24 hole aluminium tails. Without the extra holes the tails will fracture on firing.
47 gr Ballistite Mk 2 18 hole aluminium tails. No fracturing should occur on firing
47 gr. 81mm. Powder Mk 1 (smokeless, N.A production) Mazak or steel tails
55 gr Ballistite Mk 1 Mazak or steel tails. A small %tage of mazak tails may fracture on firing, but
drilling extra holes not required.
55 gr Ballistite Mk 2 Mazak or steel tails. No fracturing of mazak tails should occur on firing.
50 gr Ballistite (smokeless) Mk 1 Mazak or steel tails. NOTE Mazak was deleted by Amendment 1 in 1954.
52 gr. 81 mm. Powder Mk 1 (North American production) Mazak or steel tails.
In addition to the normal package markings of the time, here are some special markings.
'HC' has already been mentioned.
The words 'ALUMINIUM TAILS' on boxes indicates that the aluminium tails in the package are not suitable for conversion to long range firing.
The letters "LR" indicate the presence of 55 gr or 50 gr Ballistite cartridges for long range firing. In addition, the spring catches, hinges and handle hinges are painted blue and a daub or blue band is painted on each cylinder of the bomb carriers.
A large quantity of boxes produced in North America were painted service green instead of light green. To indicate the presence of smoke ammunition, while obviating the necessity of re-painting the boxes, 2 inch light green bands were painted around the ends and across the top and bottom of each end.
A 1 inch letter 'X' in a circle in red, with an EXMND date means that the bomb fuzes have been X rayed and are safe for use.
I have seen the windshield caps in service, but have never heard of it being used to differentiate fuzes for use with HE only. It is more likely to be a strengthening feature to allow you to fire in driving rain or through thin vegetation. The only other bomb to use fuzes in the 151/161 series is the Bomb 2" Mor Bomb Thrower Bursting Mk 3 filled White Phosphorous. These disappeared in the 1950s as Grenade No 80 WP, fired by Fuze Electric F 103 became the AFV screening smoke of choice. The Bomb Mor 2" Practice HE also has a removable cap, but with a big nut head in the middle.
QUOTE "It has been found that premature bursts of 2" mortar bombs fuzed No 151 have have been caused by the use of ammunition which had made an abnormally heavy landing when dropped from aircraft during exercise. Such a landing would occur from complete failure of the parachute to open or partial opening only of the canopy with the resultant failure to check appreciably the rate of descent of the attached container". This led to the modification of the Fuze 151 and the introduction of Fuze 161.
MARKINGS OF CARTRIDGES (From Amdt 1 of 1954 this applied to Mk 1 only).
Until around the end of 1944 the only markings on the cartridge case, were Makers monogram/initials and Mark.
Then this: CARTRIDGE COLOUR OF CASE PAPER COLOUR OF STENCILLING (this should be a three heading table).
47 gr Ballistite Buff Black
50 gr Ballistite Buff Red
55 gr Ballistite Buff Red
18 gr Ballistite or Hercules Green Black
17 gr Ballistite or Hercules Green Black
42 gr G20 Green Black
73 gr Ballistite Green Red (for use with SIGNAL SUCCESS to gain sufficient height for suitable signal and burn duration).
Since the end of 1944 full details of cartridges are printed along the length in ONE EIGHTH OF AN INCH LETTERS as follows:
The word SMOKELESS where applicable.
2 in ML MORTAR or 2 in BOMB THROWER as applicable (the latter obviously no longer applicable).
"SIGNAL SUCCESS" as applicable (no longer applicable)
The weight and nature of the charge.
Mark of cartridge.
Manufacturer's initials or trade mark.
In an earlier post I mentioned that mazak tails may suffer from what is known as 'mazak poisoning' and that it is possible to detect this because the tail appears to have surface lines like crazy paving. There may also be a whitish powder present. As I said before, such tails can be crushed in the hand leaving part of the central tube.
The cause of this may be contact with some adhesives, but the main cause is damp due to repeated temperature changes, accompanied by high humidity in tropical climates. I encountered this in an extinct ammunition sub depot in Africa in the early 1960s. We had to replace all stocks of mazak tails with steel tails.
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AE501,
My '45 Précis states the Long Range bombs were for use with 'Bomb Throwers' modified to handle the standard mortar cartridges. This gave them almost the same range as the mortar. Apart from the blue strips etc., and probably cause some confusion the boxes were marked either " 2" Bomb Thrower Smoke" or " 2" Tank Smoke".
TimG
My '45 Précis states the Long Range bombs were for use with 'Bomb Throwers' modified to handle the standard mortar cartridges. This gave them almost the same range as the mortar. Apart from the blue strips etc., and probably cause some confusion the boxes were marked either " 2" Bomb Thrower Smoke" or " 2" Tank Smoke".
TimG