The Garland mortar enigma

[T8HANTS]

Dave, I see what you mean about the pointer just being the bar turned through 90 degrees, and I agree the piece of flat bar appears to travel with the lever with the barrel stay between it. There must be something else though as all this is well to the side of the barrel itself as well as being slightly below the base. The photo of the one being fired off the crates does have the opperator with the leaver in his hand. From the photo Centurian has posted there appears to be another part to the side of the lever, as its pivot bolt is partly obscured by it. I am begining to wonder if the secret to firing lies within the angled wood block and a small firing hole in the base plate of the barrel which is bolted to it. Oh for a drawing!!

Gareth

[GRANVILLE]

This is my interpretation Gareth. I feel sure there is more going on inside the wooden block than is apparent. An enjoyable head scratcher nevertheless. I might add, I suspect the square metal plate you can see on the top of the block will have something to do with things - possibly an access cover to the inner workings?

Dave

[centurion]

This is my interpretation Gareth. I feel sure there is more going on inside the wooden block than is apparent. An enjoyable head scratcher nevertheless. I might add, I suspect the square metal plate you can see on the top of the block will have something to do with things - possibly an access cover to the inner workings?

Dave

I fear nothing is going on inside the block for the Garland Mortar was fired by a friction tube and a lanyard. A simple solution. In the field message book of Horace Grey, RSM Grey records many messages to Captain Hales re the Garland Mortar which was one of two mortars under Grey's command at Popes Post - it seems to have given a lot of problems such as using too much black powder for propellant charges and bombs failing to explode due to inferior gelatine. On the 5th December 1915 he requests delivery of Garland bombs, 50 charges of black powder and friction tubes (he also requests 50 bombs for the other mortar and fuse cord). 50 detonators either no 6 or no 8 are also requested and I assume these are for the Garland bombs. Friction tubes available would be the copper T friction tube introduced in 1904 for mountain guns and the 15 pdr BLC. One would be placed in the vent and the lanyard attached to the T shaped head via a piece of wire threaded through two holes in the T head. A sharp tug on the lanyard would cause the tube to turn and ignite from friction. The lanyard would come free from the wire this preventing the T head being twisted off leaving the fired tube jammed in the vent.

[GRANVILLE]

I fear nothing is going on inside the block for the Garland Mortar was fired by a friction tube and a lanyard. A simple solution. In the field message book of Horace Grey, RSM Grey records many messages to Captain Hales re the Garland Mortar which was one of two mortars under Grey's command at Popes Post - it seems to have given a lot of problems such as using too much black powder for propellant charges and bombs failing to explode due to inferior gelatine. On the 5th December 1915 he requests delivery of Garland bombs, 50 charges of black powder and friction tubes (he also requests 50 bombs for the other mortar and fuse cord). 50 detonators either no 6 or no 8 are also requested and I assume these are for the Garland bombs. Friction tubes available would be the copper T friction tube introduced in 1904 for mountain guns and the 15 pdr BLC. One would be placed in the vent and the lanyard attached to the T shaped head via a piece of wire threaded through two holes in the T head. A sharp tug on the lanyard would cause the tube to turn and ignite from friction. The lanyard would come free from the wire this preventing the T head being twisted off leaving the fired tube jammed in the vent.

I think you'd have to find a photograph of this T head friction tube if you can, because I'm certainly struggling to visualize what you describe. I can just about see the lever being used to pull back sharply on something - possibly some sort of lanyard, but how this activates on the underside of the projectile without entering the wooden block at some point is lost on me.

Dave

[T8HANTS]

Aah, the missing piece of the puzzle. I should have thought of friction tubes myself having found a few over the years from the Islands liberal sprinkling of RML guns. Do we have any detailed pictures of the type used, that would be most useful, because these will need to be replicated as well.

Gareth

[centurion]

I think you'd have to find a photograph of this T head friction tube if you can, because I'm certainly struggling to visualize what you describe. I can just about see the lever being used to pull back sharply on something - possibly some sort of lanyard, but how this activates on the underside of the projectile without entering the wooden block at some point is lost on me.

Dave

Forget levers etc, forget hollowed out blocks of wood (far too time consuming for simple beachhead workshops) Just need a friction tube and a lanyard

http://en.wikipedia.org/wiki/File:TFrictionTubeMkIV.jpg

[GRANVILLE]

So what would you suggets the lever is for? Its clearly got a purpose.

[GRANVILLE]

Maybe this helps? I presume this is one of the T head friction ignitors Centurion mentions, and the other is an even simpler divice just to show the principle. I can now see how the ignitor tube is inserted into a hole in the side of the breach, and presumably it was originally intended for the lever to engage with the ring-pull. When the lever was sharply depressed it would pull back and bring the ignitor ring pull with it. As Centurion suggests you could do the same job by just attaching a lanyard, but I presume this was what the lever was originally designed to do.

Dave

[centurion]

Except that's not how the T Tube worked. There was a later version of the T tube that had a percussion cap in one arm of the T head and a powder tube connecting to the part that went into the vent. This removed the need to thread a lanyard onto the tube in an attempt to increase the rate of fire from those guns still using bagged charges. A device was provided to fix to the breech to allow a spring loaded 'tapper' to fire this. However these new T tubes did not come into use until about Feb 1916 well after the date that RSM Grey was reordering friction tubes for his Garland. I can only conclude that the Garland was originally made for the old T friction tube (nice and simple) and the one seen at Quinn's Post has been later modified to use the new version (possibly because the old tubes were becoming unavailable). This raises the interesting possibility that the one in the museum is the remains of the Quinn's Post mortar with bits missing.

[GRANVILLE]

Forgive me if I seem confused by the wealth of information Centurion is able to supply, but in post 31 you provided a link to T Tube friction ignitors which you suggested were used to fire the Garland. Eureka, and it all seems clear except when I post a picture of a Tube ignitor with suggested direction in which a lanyard or the lever arrangement would act on it, you state that this is not how they worked?

In the link you posed the instructions are pretty clear:

• The gunlayer inserts the tube in the breech vent.
  
• A lanyard is attached to the loop in the wire in the T.
  
• The gunlayer pulls, or extends and "chops down on" the lanyard.
  
• The friction wire is pulled through the detonating composition and out of the head, igniting the detonating composition by friction.
  
• The flash passes down the small hole in the top of the body, over the copper ball, through the fire-holes in the brass screw-plug, and ignites the powder.
  
• The expanding gas forces the copper ball up into the cone seating, sealing the vent on the inside of the tube, and expands the tube body, sealing the vent outside the tube.
  

It all seemed to make perfect sense to me up until this point. An igniter of one form or another would have been inserted into the side of the block - the access hole most likely hidden from view by the upright steel bar that can be clearly seen. The friction wire with loop obviously had to be pulled back sharply to effect ignition and to me it’s perfectly clear the lever and spring arrangement were originally designed with this in mind - what Gareth referred to as a pointer may well have been drawn to something of a point in order for a custom made wire or rope to run from it to the loop of the igniter. If, for whatever reason the lever arrangement did not give satisfactory service I can well imagine a simple lanyard being employed for the purpose. Seems pretty clear to me?

Dave

[T8HANTS]

I have been thinking along similar lines, with the addition that the rivited on piece of flatbar attached to the 'pointer' may have been there to act as a guard against the friction tube blowing out on firing and whistling off down the trench. I know the small copper ball was supposed to stop this happening, but this was non-ordnance grade comparatively thin walled tube, so I would have thought a blow out highly likely. The only thought is why such a complicated firing mechanism, when a piece of hairy string would do the same job? Although jerking a lanyard may well have moved the mortar off target, the lever would have produced less jerk.

Below is the official photo of the relic barral brought back from Lone Pine, again no firing hole is visible or described, which is no help.

Gareth

[GRANVILLE]

Gareth. Personally I wouldn't expect to see a firing hole in the barrel which would have been pressed into the wooden block base. I think the igniter access hole will have been in the side of the wooden block in the vicinity of the bar you described as a pointer, which will have been chambered inside to give access to the charge, presumably dropped down the barrel prior to the projectile being inserted. This is one of the reasons why I think there is more to the block and the metal plate on the top quite possibly covering access to the inside for maintenance; bearing in mind how basic & primitive the weapon is.

Dave

[Chris Henschke]

The "L shaped handle" is not a handle. It is a foot lever used for firing the friction tube.

The gun is fired by an ordinary friction tube, by means of the foot lever. The loop of the tube slips over the lever.

The barrel (when it hasnt been cut down!) is 18 inches long, is removable and fits into a brass breech piece with powder recess, bolted to the wooden stand.

The cartidges are made up in little bags, each one being marked with its weight, the different sizes being of different coloured cloth. The charges are arranged so that by varying the number and size any weight of charge can be put in the gun.

The Mark II was modified so that it could be fired using a friction tube like the Mark I, or by means of a shotgun cartidge case.

Chris Henschke

[Chris Henschke]

Here is an image of the bomb.

[T8HANTS]

Chris

Thanks for you replies which I have just spotted. You have confirmed that there had to be a powder chamber within the wooden block, and it is interesting that it was brass.

Do you know if the more complete example in my post 1 is part of the AWM collection, as it doesn't turn up in their online catalogue. I would love a better photo of the beast, and would also like to know what is on the brass plate on top of the wooden block.

Thanks for the excellent diagram of the grenade.

Gareth

[Chris Henschke]

Gareth,
I can't confirm where your image is from, but given the reference to 3rd Light Horse Brigade on the sign next to it, probably in the AWM. The brass plate is probably the range table showing the charges to be used for various ranges. The barrel was set at 45 degrees and the normal way of altering the range was by varying the charge. Raising the front or back was an improvised method.
If you make a replica, the bronze safety and firing pin is prevented from falling out by a piece of wire which passes over the head and is secured round a small nail head.
Chris Henschke