Nitrate Film

[Tony Milman]

Just sharing this for the amusement value. I have never come across Nitrate film but obvioulsy have heard about its flammable properties.
Whilst clearing the attic of my late father-in-law i came across a dusty box of old 35mm films....you guessed it....all nitrate. It's a miracle that the house didn't burn down.
It did not take very much to set fire to them and the heat output was something quite extraordinary. It's a shame they couldn't be saved but were too unstable. Makes me respect the projectionists of old

[Maurice Leakey]

As I have said before.
As a trainee Odeon projectionist, aged 17 in 1952, our Sunday films were always nitrate, and they only arrived on 1000ft cores so I had to join 1 to 2, 3 to 4, etc., to make 2000ft spool runs.
However, joining nitrate was very easy, providing I used the correct cement.


Maurice

[Lee Mannering]

A story of silly me the amateur 35mm home projectionist in the 1980s.

Back then yearned for a 35mm projector and had been offered a GBN ex Navy wartime projector. My neighbour offered to pick it up in a estate car and we travelled back with it and rusty cans of film with the rear of the car hanging very low.

Modified the projector to a 500 watt lamp and external amplifier. We started giving show to old b&w film fans locally projecting George Formby and Gracie Fields really great fun and loved every minute weekend after weekend.

The sucker punch.
A local retired professional projectionist from Unit 4 cinema popped round to view the setup somewhat impressed with the old GBN projector. He asked to have a peek at a film pointing to its edge which said NTRATE along the edge.
you do realise this film is inflatable?

That was my learning curve where my enthusiasm had taken over after which I made sure all films were on safety stock as of 40 years ago. More than dangerous and a lesson learned.

I set fire to 5ft for a documentary i was making a few years later about projecting Nitrate and the heat was phenomenal from the film.

[Simon Wyss]

In past years when people still had their senses together, if not their natural share of common sense, it was possible to raise a conscience with them. Projectionists would learn how a show is prepared, how a print is gone through, and how it is run on a pair of projectors. Professional projectionists would have the right touch, movements as second nature, in short routine. I was one of them and along the many manipulations we did we detected the slightest deviation from normal. We got acquainted with a print over the weeks, knew every detail from shrinkage amount to displaced soundtrack. Nitrate film can be exploited without explosions. My explanation.

[Mark Mander]

Its incredible how dangerous Nitrate can be, if you didn't know you wouldn't fear it, found lots of it when we cleared an old cinema years ago and never gave it a second thought, might think twice now though, it's a bit like finding asbestos in a projector I bought, i did dispose of it straight away but I'm sure it didn't worry users years back, Mark

[Joe Caruso]

Nitrate is the reason why 80% or more of the earliest films are gone....save for some fragments - Shorty

[Brian Fretwell]

More than just flammable, nitrate produces its own oxygen as it burns and can carry on burning under water. The NFT nitrate registered projectors in NFT2 have plumbed in CO2 extinguishers, gun cotton by the gate with shears to cut the film either side and isolate the reels. Also they will bring down shutters over the projection ports isolating the projection box from the auditorium.
All this was shown/explained on a members tour some years ago. The video of the nitrate vault they had set alight (after copying the contents to safety film) wa more than frightening, with the wooden framed steel door being thrown through the air with the force of the gasses inside.

[Terry Sills]

I think the danger of Nitrate film is somewhat overstated. It needs flame or extreme heat to make it combustible and don't forget it was regularly used in cinemas with only very rare disasters and the projectors that ran it were using carbon arc lamp houses. Projectors of that era normally had a 'fire trap' to kill fire if it occurred during a show.
Obviously great care is necessary handling Nitrate but it did give a superior picture definition compared to other type of film.
I have heard that over time Nitrate decomposes to Nitroglycerin but I think that's a bit of a myth.

[Maurice Leakey]

Our 35mm BTH Supa projectors had carbon arcs that ran at 75amps, 50volts. That's 3750 watts of heat.
Above and below the spool box firetraps they had spring guillotine blades held back by a frame of nitrate film. In the event of a film fire, the two guillotine blades severed the film at each film trap. The small section of exposed film would be allowed to just burn.
It never happened.

Maurice

[Terry Sills]

Maurice, an experienced Cinema projectionist, makes my point. Fires were very rare and the firetraps eliminated anything serious. Fire has to have three constituents - Heat - Fuel - Oxygen. Eliminate any one of these three and the Fire is extinguished. The firetraps eliminated fuel by allowing the small section of film in the trap to burn itself out.