28 replies to this topic

[GZ22]

I've just posted that link you posted MDH in the Joyce Green thread.

[amandaf2115]

Spectrum,

Did your old boss ever know the owners of brocks fireworks personally?.........if so, would he happen to know the whereabouts of the related families?


I believe there is Andrew Brock (somewhere) who`s father (not sure of his first name...deceased) was the last decendant of the brocks who made or managed one of the factories!

Pyrotechnist:- Ive sent you a email!

With regards to your question about the Brocks - my parents do have some information on the family - please see below.

His father was called Benjamin Arthur Brock, son's Andrew and Simon Brock. Andrew appx. 44 years old now and Simon (42). My Mum and Dad worked for Benjamin Brock at Swaffham Brocks for approx. 10 years. When the Brocks moved out of the house at Castle Acre Road, my parents moved in. SImon, Andrew and Mrs Susan Brock live in the Dereham area.

My parents are looking to catch up with any old work colleagues from the period April 1958 - June 1973.
Any help would be appreciated.
Amandaf

[Mortartube]

As far as I am aware, one of the Brocks (possibly Andrew) now works in the tobacco industry. This came from a member of the firework industry who has met him.

I will have to check my info next time we chat.

[amandaf2115]

Thanks for that Mortartube.

All the help offered is appreciated.

Amanda

As far as I am aware, one of the Brocks (possibly Andrew) now works in the tobacco industry. This came from a member of the firework industry who has met him.

I will have to check my info next time we chat.

[amandaf2115]

Nothing remains of the old Breocks site although another company has licensed a pyrotechnic factory near to where they were based but simply havent got around to developing and building the place yet.

My old boss at Astra used to work for Brocks, we were talking about Swaffham only very recently and he described the set up to me. From what I know they used to extrude-fill the fireworks on that site. I did have an old plan (original one too) but I lent it to a shit of a man which, along with a fairly large label collection, he kept. Don't trust anyone!

My mum and dad who used to work at Brocks, Swaffham, said that yes they did used to extrude-fill the fireworks on site. If you want to know anything else, just ask and I will ask them.
amanda

[pyrotechnist]

what do you mean by 'extrude-filling fireworks'? what process is that, never heard of it before.

[Mortartube]

Extruding is basically mixing the composition with a resin and pumping into tubes, in a similar way that meat is pumped into sausage skins.

But not any resin will do. Resourcinol resins are often used, they are expensive and messy but certainly speed up manufacture.

[dr thrust]

those motors must be pumped under extreme pressure?, looking at a modern shop bought firework rocket motor that employs a resin binded comp system, they are enclosed in a thick walled tube, and the tube is usually deformed/ bulged near the bottom.
can anybody divulge what those tubes are made of, nylon?.
on a more nostalgic note ive tested a few 1lb motors this evening, with a Brock bp rocket propellant 13,7,2 from his book " a history of fireworks" with excellent results

[Mortartube]

Most of the Chinese motors that I have seen in the plastic tubes (usually transparent tubes), are not resin bonded but simply pressed. Probably at 100 or more at a time. They are very simple motors end burning with a very deep clay choke and a small increment of fast BP.

They are cheap and cheerful, but they do work and the wall thickness of the tube means that anything untoward with the propellant is not likely to shatter the tube as there is such a small amount of propellant in there.

There is no need to pump resin bonded propellants into a tube under very high pressure as they will just ooze from the mouth of the tube. Think of one of those plastic syringe cake icing kits, that is nearer to the pressures and method of filling extruded motors etc.

Some extruding machines have a spiral to drive the mix forward. like the old tabletop meat mincers. That way you just chuck the mix in the top and it can be a fairly continuous process if you keep the hopper full of mix.

Needless to say you must clean the machine thoroughly at regular intervals or resin will set and clog the whole thing up.

Edited by Mortartube, 26 April 2009 - 09:24 AM.

[dr thrust]

interesting, i wounder what the Chinese are using for a propellant in those cheap and cheerful motors then?
is it straight bp?, the one's ive "inspected where of a reddish color, i just presumed they where resin, they looked waxy indeed they are very reliable and use a minimal amount of propellant with great results
it would be nice for the " home hobbyist"to be able to mimic them, with "plastic"? tube and all to reduce the weight of amateur firework rockets as what goes up must come down, as cardboard seems a little to heavy which is always a worry

Edited by chris m, 26 April 2009 - 11:06 AM.

[Mortartube]

They may be resin bonded if reddish in colour, but the clay from certain areas in China is red. From terracota plant pot red to a pink colour dependent as to the area. Are you sure it wasn't clay that you saw. If it definitely was propellant then it was possibly resin bonded or it may have been a non BP mix with iron oxide added to boost the burn rate.

[dr thrust]

dam i wish i kept the motor, the clay in the bottom of the motor was a white color and the tube was deformed from pressing, therefore would it be conceivable that a powdered resin could be add to the comp then pressed rock hard saving all the problems of cleaning up the machinery of a wet resin system?

[Mortartube]

It is unlikely that a dry resin would be added to a comp unless it was specifically there as a fuel. Many resins act as a retardant and slow the burn rate. Not desirable in rockets once you have a good propellant formula that works well. It would also add dramatically to production cost.

The motors are probably just fast BP pressed under a high pressure to ensure no CATO's. I bought some little rockets last years (Firework Factors Brand - Comets & Whispers) and they do not have a long steady burn, the BP inside burns almost instantly like a stage silver jet and the momentum seems to keep them going up to about 20m - 25m, before the header bursts into flying fish fuse.

Could your tube have become deformed through the heating effect when the rocket was fired? The internal gas pressure adding to the bulge effect.

[dr thrust]

the rocket motor was unfired, it was left over from a nov 5th back yard display and so a few days later out of curiosity i did an impromptu autopsy to see what it was all about. thank you for taking the time to answer my questions , i just wish i kept it for reference, i have heard of a potassium perc, red gum propellant, but cheap and cheerfull's wouldn't be using that!