Monday, 4 May 2015

Royal Gunpowder Mills and VE Weekend

For more than 300 years there has been at least one water powered mill at Waltham Abbey.  The first was a cloth fulling mill which was subsequently converted to produce vegetable oils.  Sometime after 1667 the mill was again converted.  This time to produce gunpowder.  The components of gunpowder are saltpetre, charcoal and sulphur.  When mixed in the correct proportions they will produce an explosion on ignition.

The mill remained in private ownership until 1787 when it was acquired by the Crown.  Whilst the mill primarily produce gunpowder for the military, it also had a commercial side producing explosives for tasks such as quarrying, tunnelling and mining.  Gunpowder was produce until the late 19th century when it was replaced by cordite.

Cordite is a mixture of nitro-glycerine and gun cotton. Gun cotton is made by forming  nitrating cellulose.  Both gunpowder and cordite are slow explosive which are good for ‘heaving’ or ‘propelling’.  As such they don’t damage the barrel.

Production at the Royal Gunpowder Mill increased significantly during WW1.  The workforce nearly doubled with half the employees being female.  Two major accidental explosions occurred during WW1 which resulted in a number of workers being killed and buildings destroyed.

The mills continued to produce cordite through the first half of WW2 before production was moved to various other locations.  The mills then focussed on explosives research and eventually on rocket propellants. The research centre closed in 1991 and the entire site is now a tourist attraction.

I wanted to visit the mills because I’d read a canal system was used to move the ingredients and final products around the site.  I also wondered if there was a link between the mills and ‘blow-up bridge’ in London. It seemed logical that the gunpowder would be moved by water from the mill to various magazines around England.

Originally the mill had two separate canal systems on different levels.  This was a safety measure where raw components were transported on one and the final product on another.  As the mill continued to expand the two were combined with the construction of a lock.  The remains of the lock can still be seen.

The mill continued to expand and eventually a narrow gauge railways was constructed.  Carriages were moved using manual labour (ie, by two men) but eventually small locomotives were used.  Wooden rails were initially used to avoid sparks between the wheels and rail. Brass rails were rejected on cost.

A rebuild covered canal boat used to move material around the site

Many of the building are overgrown and crumbling away.

When the cordite had been mixed it was in a paste form.  This was then put into a large hydraulic press and squeezed out as long tubes, the dimension of which depended upon the final purpose. 

1939 hydraulic press.

The final product had to undergo a number of quality tests.  One such test involved the following apparatus.

The mouths of a cannon and mortar were placed facing each other 2” apart.  The propellant was placed in the cannon which was on wheels.  The propellant was remotely detonated and the resulting explosion would force the cannon backwards.  The mortar barrel was mounted on a swing.  The amount of backwards swing was recorded and this established the strength of the propellant.

I probably would not have spent the entire afternoon at the mills except they were celebrating the anniversary of Victory in Europe (VE Day) Weekend.  A large number of enthusiasts had arrived to participate.  There was to be a fly-over by a WW2 P51 Mustang followed by a battle re-enactment.

On safety grounds the P51 was forbidden from flying directly over the site.  Apparently the Mustang was an original WW2 aircraft (not rebuilt) and still had the signs of repaired aerial battle damage.

On the ground the participants were in the early stages of preparing for their battle.

The Welsh Guards were having a team talk.

Whilst the paras just seemed to be waiting

The Germans didn’t seem to realise they were about to be hit

Sergeant Schultz put in an appearance

There appeared to be too much fraternising.  But then with only five bullets each the battle wasn’t going to be that long.

At least no one permanently died. Smile

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