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ivorthediver
03-07-2009, 17:42
Can anyone explain to me how the charge in the larger guns was ignited please

I realise that in the smaller guns the charge was set in a larger type of round not unlike a rifle round and was fired by some sort of percussion device but in the large calibre guns I have seen the shell pushed into the breach followed by a Charge wrapped in what I believe was a silk bag but how was it detonated as there is no apparent means of igniting it :confused:

ivorthediver
04-07-2009, 06:18
Where are all the gunnery boys hiding then......I would have thought some of you are still alive and kicking out there:confused:

patroclus
04-07-2009, 06:45
Can anyone explain to me how the charge in the larger guns was ignited please

I realise that in the smaller guns the charge was set in a larger type of round not unlike a rifle round and was fired by some sort of percussion device but in the large calibre guns I have seen the shell pushed into the breach followed by a Charge wrapped in what I believe was a silk bag but how was it detonated as there is no apparent means of igniting it :confused:

In large BL guns in RN service vent tubes and igniters were used. Vent tubes consisted of a means of ignition and a magazine of powder pellets and loose powder contained in a small brass case. The powder pellets, when ignited flew, burning, into the igniter and ignited it. Vent tubes were of two types - electric and percussion. The electric tubes were fired by an electric current passing through an electric lock. When this current was switched on, by the gun-layer or director-layer pressing his trigger, it flowed along a thin iridio-platinum wire "bridge" surrounded by explosive inside the tube. The bridge fused almost instantaneously, and ignited the explosive and the powder pellets in the tube magazine. Percussion tubes were were fired by the blow of the striker of a percussion lock. A flash from the cap ignited the powder pellets in the tube magazineThe igniter consisted of gunpowder in a red shalloon bag, sewn over one or both ends of the cartridge. The gunpowder caught fire more readily than cordite and ensured that the flash from the tube set the cordite alight.

Source: "Gunnery Pocket Book 1945.".

ivorthediver
04-07-2009, 19:01
Thank you so much Patroclus , that question has been bugging me for ages as I have never noticed anything like that in any film/documentary I have seen yet the Shell case round was fairly obvious

Was there any debris left in the breach after firing a round in that manner or was it all expelled.?

patroclus
04-07-2009, 22:12
Everything was consumed in the explosion.

ivorthediver
05-07-2009, 05:54
Everything was consumed in the explosion.


Thank you for your help and explanation

tim lewin
05-07-2009, 20:19
You did need to swab the breech for glowing embers with a damp mop in some guns whith a thing on a stick most appropriately named a "Wooley-headed bastard"! Surely some of our prof gunnery chums will expound on these.
tim