Turret-mounted "2-inch bomb thrower" in British tanks

Guys, I'm trying to find out more about this little number tucked away in the turrets of most British tanks - it fired through the mantlet on Convenaters, Valentines and the first two marks of Crusader...and through the turret roof in Churchills, Cromwells, Comets etc....

It fired the same two HCE and WP smoke rounds as the ML 2in infantry mortar...but at a GREATLY reduced range, down around 150 yards apparently. And seems never to have been used to fire any 2-inch H.E. rounds...?

In later installations it fired at a fixed elevation - the top end of the "tube" was welded to the turret roof Here's the Cromwell installation...

Pop the round in the lower half of the hinged tube...



...then close the "breach" and lock with the lever-assisted locking ring...




...screw up the gland nut attaching the gas port extension to the exhaust leading to the outside of the turret....and fire!

The "gas port" bled off propellant gases and a regulator on the port (out of sight in that diagram?) helped reduce the mortar's range down from the "bomb thrower's" 150 yards for close-in protection/screening..

What I'm trying to find out is what happened in the earlier installation - the early Valentine/early Crusader/Covenanter one???

I haven't managed to turn up any inside-the-turret pics of these earlier tanks that show THEIR bomb throwers...but you can see the open end of the mortar tube HERE on the starboard side of the turret just beside the main gun/coax MG...

 

It SEEMS as if it elevated in these early installations....did it?

And if so - how did they bleed their excess propellant off? Did they just vent into the turret...or was there a flexible section in the exhaust pipe?

Does anyone have a pic or drawing of the Valentine/Covenanter/Crusader installation?

 

the mkiv Churchill had the same smoke bomb thrower with the exception of the exhaust installation - ONLY smoke bombs of which we

carried a dozen each day..only used it once and the wind from the Adriatic carried the smoke away from the troops it was supposed to

cover ..bad day all round I guess as the smoke gave away our position…and the 88mm didn't miss…

Cheers

 

Hi Tom.....so it's not just an ommission on the diagrams of the Churchill installation I've seen, it didn't have the exhaust pipe? That's good to know!

So did it just not vent propellant at all, can you remember? Just a fixed range?

 

From Dick Taylor's Into the Vally. Annoyingly, it doesn't clarify whether it had fixed or independent elevation...

 

I know, it's yet ANOTHER of those elusive little details! Looking at the Covenanter port...which is vertically elongated...I'd guess it could be elevated - but I don't want to have to guess LOL


Here's a simple question for anyone on here who's ever used a mortar...

If you use exactly the same mortar round in exactly the same weapon - but on one the tube is twice as long as the other - will the round fired from the longer tube go further because of the higher muzzle velocity?

I know this is Ballistics 101...but I'm down at that level LOL

 

I only ever used a 2'' mortar on the range or for illumination rounds on exercise and can't offer an informed opinion on comparing length of tubes but there is potentially a problem using the same rounds from short and long tubes whereby the hot gases from the propellant could damage the base of the bomb if fired from a very long tube. I suppose there is also the possibility of the bomb 'cooking off' in the tube in such circumstances. Sorry but I don't seem to have advanced this any further have I? CS

 

The Churchill 2" smoke bomb thrower was a fixed range weapon with No adjustment NOR ventilation - used in support of our Infantry -

in most of our squadron's tanks - as I recall.

Cheers

 

Or read a book!

The example that sprang to mind was the 2" mortar itself, as there was the shortened 'airborne' version. The standard 21" barrel could achieve a range of around 500 yds, the 14" airborne version managed about 350 yds.

 

Just found a photo of a photo here:

http://scaleplasticandrail.com/kaboom/index.php/all-things-military-vehicle/everything-else/book-reviews/1264-valentine-tank-walk-around-from-squadron

Click on the 3rd group of photos; first photo shows 2'' thrower in position in turret of what I think is a Mark 3 Valentine. It certainly looks as if it could be elevated/depressed.

CS

 

You have NO idea how many Google "mortar" links I've clicked on only to find herbs and spices! LMAO

Tom, thanks again! That would confirm that the 150 yard range listed for the Churchill item was indeed without venting...so the venting in Cromwells and later was indeed to shorten the range. I'm getting there!...

...ditto for this, Idler! The actual "tube" on the tank items seems to have been a good deal shorter than 21 inches in total! Pity I can't find any written details on that aspect

It does indeed...tho' maybe not by much. Interesting that the loader got his own periscope in the 'thrower-equiped Valentine...!

 

I'd describe it as a 'grenade projector'. Remember the No 36 grenade was often called the Mills Bomb. Of course post war they were entirely external, fitted in clusters on the turret with an electrical firing mech. The current ones use RP smoke, not sure about RP in WW2 but IIRC it was used in some smoke grenades. As a screening smoke its much more effective than WP and less noxious if your own infantry are nearby. For UK arty RP has now replaced HC. For a range of about 150 yds I'd suggest that they could have been propelled by a ballistite cartridge, the same thing as was used for rifle grenades. I've only ever used HC smk with a 2-in mortar.

 

Mapshooter, thanks for the above...AND the earlier comment about mortar rounds and very long tubes, that illustrated there`s a maximum practical length as well as a minimum!

 

I'm sure you'll be delighted to know I bought today a beautiful mortar and pestle set made of polished green granite. The range is as far as i can throw it.

 

Chaps,

Some photos of a 2'' thrower in a glass case at the Cobbaton Collection, Devon. The photos are a bit shonky but the best I could do.

CS

 

As a wireless op in Light Ack Ack, we occasionally found ourselves at the receiving end of Jerry Nebelwerfers which, as Brian correctly pointed out, were more often known as Moaning Minnies. When I finished up in the Hussars, for whatever reason, they had stopped using these contraptions and seemed to rely more on mortars and spandaus.

The peculiar noise the Nebewerfers made was in itself fairly bowel loosening and before they had even finished their "pattern" the hot metal was landing at the receiving end.

On our Honey tank we had a 2" Mortar fixed to the chassis ring on the right (looking forward, that was) but I can not remember ever firing it in action.

What I do remember however, is on the day when the war finished in Italy we were told that "as from midnight, all ammo will have to be accounted for".

By general and unqualified consensus, we fired off all our 2" mortar shells and, into the sky, all our remaining .30 & .50 Browning ammo as part of a bloody great fireworks display which signified to everyone in the area that we had finished our part of the war.

ps
Just went back to my Diaries and found this entry:
Quote
Wednesday 2nd. May 1945
Jerry threw his hand in in Italy & Austria. Fired all our 2" mortars, phosphorous bombs & verey lights & had bonfires all over the shop.
Cease fire about 11 pm.
No mention there of the .30 & .50 ammo so now I've got to rely on my memory.......sod it !!!!
That will teach me to consult my diaries first
Edited by Ron Goldstein, 17 April 2009 - 05:08 PM.
Added text

 

Hi,
This picture shows the location in a Crusader II.

Regards

Alistair