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4.5" howitzer gas shell drawings ....
- Thread starter starshell
- Start date
During WWI there were three designs of 4.5 inch projectiles, which entered service and evolved as a result of development throughout the war.
Firstly there was the “Solid Head” projectile which was a modified HE projectile, filled through the fuze well and fuzed with the No 44 fuze. The length was approximately 320mm, but this could vary depending on the manufacturer. This design had a very poor chemical agent to weight ratio, with the chemical fill being only 1.7kg of the overall 15kg weight. Furthermore, being a modified HE projectile, the walls were very thick (up to 23mm) and as such the dissemination efficiency could have been expected to be poor as well. Finally, this projectile can be found with both the wide and economy driving bands (Picture 1 and 2).
Next was the “Double Diaphragm” projectile measuring 370mm in length. The nose section containing the explosive burster charge screwed onto the body of the projectile and was sealed with a double diaphragm comprised of two steel plates (3mm thick) which were an attempt at sealing the top of the projectile body prior to the installation of the nose. The projectile was filled via a hole in its side, which was sealed with a lead plug. This projectile can be found with both the wide and economy driving bands and was fuzed with either the No 44 or No 106 fuzes. The double diaphragm design contained between 1.0 and 1.5kg depending on the chemical agent (Picture 3).
The third design was known as the “Container Type” projectile which measured approximately 340mm in length, but this could again vary depending on the manufacturer. The wall thickness was 15mm and this design was filled through the side. The container was an explosive burster which screwed into the neck of the projectile and depending on the chemical agent fill contained 170g of fumyl. The British realised early in the war that different chemical agents required different quantities of explosive to be disseminated effectively and hence varied the amount of explosive in the burster by inserting a wooden block, stamped with markings to indicate which chemical agent it should be used with. This projectile can be found with both the wide and economy driving bands and was fuzed with either the No 44 or No 106 fuzes. The container type design contained between 1.0 and 1.5kg depending on the chemical agent (Picture 3).
In addition to the three designs above, there were a number of other designs which were developed during the interwar years.
Cheers
Pete
Solid head
Solid head cut
Double diaphragm missing ogive
Container type with No 106 fuze
Container type showing filling plugs
Firstly there was the “Solid Head” projectile which was a modified HE projectile, filled through the fuze well and fuzed with the No 44 fuze. The length was approximately 320mm, but this could vary depending on the manufacturer. This design had a very poor chemical agent to weight ratio, with the chemical fill being only 1.7kg of the overall 15kg weight. Furthermore, being a modified HE projectile, the walls were very thick (up to 23mm) and as such the dissemination efficiency could have been expected to be poor as well. Finally, this projectile can be found with both the wide and economy driving bands (Picture 1 and 2).
Next was the “Double Diaphragm” projectile measuring 370mm in length. The nose section containing the explosive burster charge screwed onto the body of the projectile and was sealed with a double diaphragm comprised of two steel plates (3mm thick) which were an attempt at sealing the top of the projectile body prior to the installation of the nose. The projectile was filled via a hole in its side, which was sealed with a lead plug. This projectile can be found with both the wide and economy driving bands and was fuzed with either the No 44 or No 106 fuzes. The double diaphragm design contained between 1.0 and 1.5kg depending on the chemical agent (Picture 3).
The third design was known as the “Container Type” projectile which measured approximately 340mm in length, but this could again vary depending on the manufacturer. The wall thickness was 15mm and this design was filled through the side. The container was an explosive burster which screwed into the neck of the projectile and depending on the chemical agent fill contained 170g of fumyl. The British realised early in the war that different chemical agents required different quantities of explosive to be disseminated effectively and hence varied the amount of explosive in the burster by inserting a wooden block, stamped with markings to indicate which chemical agent it should be used with. This projectile can be found with both the wide and economy driving bands and was fuzed with either the No 44 or No 106 fuzes. The container type design contained between 1.0 and 1.5kg depending on the chemical agent (Picture 3).
In addition to the three designs above, there were a number of other designs which were developed during the interwar years.
Cheers
Pete
Solid head
Solid head cut
Double diaphragm missing ogive
Container type with No 106 fuze
Container type showing filling plugs
Many thanks for the information Pete. Very interesting. I wasn't aware of so many variants of gas for the 4.5" so am now enlightened.
The reason for my original question was I thought I might have a 4.5" gas variant owing to the fact it had a grub screw in the ogive, but cleaning the interior has revealed it to be a screw to secure the threaded ogive in place. (see pics).
Besides, I've always believed (but could be wrong), and as you mentioned, gas shell filling holes were plugged with lead? Were grub screws ever used?
Cheers,
DylanView attachment 128099View attachment 128100View attachment 128101
The reason for my original question was I thought I might have a 4.5" gas variant owing to the fact it had a grub screw in the ogive, but cleaning the interior has revealed it to be a screw to secure the threaded ogive in place. (see pics).
Besides, I've always believed (but could be wrong), and as you mentioned, gas shell filling holes were plugged with lead? Were grub screws ever used?
Cheers,
DylanView attachment 128099View attachment 128100View attachment 128101
Hello Fert,
A lot of Mk were manufactured for 4.5in chemical shells.
-First trials, short shells (315mm w/f), with solid head screwed fuzed No44, used a special shape for chemical. As far as I know, no HE shell with this design.
I've never heard about Mk's for this family (quickly obsolete).
-Long shells (364mm w/f) with head screwed and diaphram were made with few Mk.
Special design only for chemical filling (or WP...). No HE shell with this body. Most common is Mk3 (with different type of chemical filling)
-Then a lot of Mks came with container type. Different sizes (330mm to 342mm, same as HE).
They used body of HE shell modified with special gaine (Mk of HE shell used change with a new Mk for gas shell)
They also made bodies only for chemical filling with specific Mk.
So a lot of Marks for this family.
I know MkIV to MkXIII (!) maybe more...
It's very hard to make difference of Mk when we collect these shells from the ground !
Sometimes it's possible to read markings on the base.
-For example :
.Mk IV chemical shell (container type) is converted from Mk V or Mk VII HE shell
.Mk V or MkX chemical shells (container type) are not converted HE shells.
etc...
A lot of Mk were manufactured for 4.5in chemical shells.
-First trials, short shells (315mm w/f), with solid head screwed fuzed No44, used a special shape for chemical. As far as I know, no HE shell with this design.
I've never heard about Mk's for this family (quickly obsolete).
-Long shells (364mm w/f) with head screwed and diaphram were made with few Mk.
Special design only for chemical filling (or WP...). No HE shell with this body. Most common is Mk3 (with different type of chemical filling)
-Then a lot of Mks came with container type. Different sizes (330mm to 342mm, same as HE).
They used body of HE shell modified with special gaine (Mk of HE shell used change with a new Mk for gas shell)
They also made bodies only for chemical filling with specific Mk.
So a lot of Marks for this family.
I know MkIV to MkXIII (!) maybe more...
It's very hard to make difference of Mk when we collect these shells from the ground !
Sometimes it's possible to read markings on the base.
-For example :
.Mk IV chemical shell (container type) is converted from Mk V or Mk VII HE shell
.Mk V or MkX chemical shells (container type) are not converted HE shells.
etc...
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