Coffman engine starter cartridge use

The first 36 seconds of this YouTube video shows a Coffman engine starter cartridge being inserted into the firing device. The aircraft is a WW2 U.S. Navy “wildcat” fighter.

A comment by “Conrad” explains the functioning in some detail and is worth repeating here:
“The Coffman starter uses a specially made 4 gauge paper shell with an electric primer. It is filled with .25” and .187" diameter cordite pellets for slow burning powder. The shell fires into a starter assembly on the accessory case of the engine, same position as an electric starter. It DOES NOT fire directly into a cylinder of the engine. The gasses force a piston inside the starter assembly forward towards the engine collapsing spiral gears on top of each other converting it into a circular motion. This engages the starter dog and rotates the starter gear. After the piston reaches the end of its travel a valve released the residual pressure and a die spring resets the whole process."

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Nice to see how these starter cartridges were used.
There are 3 tins of them for sale locally in Ballarat if Aussie collectors are interested.
The labels are poor or missing on the lids.

very neat, thanks John

Great video, John. Thanks. I was a bit concerned about all the fuel pouring out of the bottom of the engine cowling as the engine started. All the blue/gray smoke was normal for a radial engine like this during start as oil that pooled in the engine as it sat before start was burning off.

Been posted before. Some of my random engine starters

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