A Belmont Club thread linked to this great scene from the movie, Flight of the Phoenix. I saw that movie on TV when I was a kid, and ever since I wanted to know what a Coffman Starter was. And now there is the Internet. Drunk with power, I googled… and found this web site. Holy cow. I emailed the URL to Lex and he replied, “Fragments, like dinosaur bones.” He got that right. In a couple of hundred years, who is going to know what any of this stuff was?
(BTW, it appears that a Coffman Starter works by directing gas from an exploding cartridge against a piston, which is connected to a shaft, and that this shaft turns the engine. If that’s the case, how could James Stewart “clean out the cylinders” by firing a cartridge with the ignition off? Wouldn’t he have merely turned over the engine without cleaning out anything? Perhaps the movie makers used some artistic license here.)
9 thoughts on ““Dinosaur Bones””
That style of starter cartridge was used in F4Fs in WWII. I don’t know when the electric starters appeared in war planes. Also, most ground crews pulled the prop manually around a few times to get the oil out of the low cylinders before firing the starter cartridge.
I have harbored the same curiosity for decades. I saw the movie but once, and the starter scene has stayed prominent in my memory all those years. Thanks!
I wonder if the cartridge starters fell out of use in part because the primers in the cartridges caused corrosion in the starter mechanism. Noncorrosive ammo wasn’t widely used until after WW2. If the cartridge starters used corrosive primers it would have been necessary to clean them after every use. Compressed-air and electrical starters probably require less maintenance.
“Cleaning out the cylinders” was necessary after an old radial engine sat for a period of time because the oil (and any gasoline) left in the upper cylinders at shutdown would pool in the lower ones due to gravity. That made a start hard because the plugs in the lower cylinders would be fouled, and the fuel inlets could also be fouled. If you watch film of the start up of an old radial, the belch of black smoke right after start is all the junk burning off the cylinder walls. It was especially bad if the engines weren’t properly shut down by turning off the fuel feeds and letting the engine quit due to lack of fuel.
If I recall the story correctly, the C-119 crashed into the desert while the engines were running, so they’d have a lot of residual fuel and oil in them, hence requiring that they be cleared by turning the engine over a few times with the cartridge.
Another cartridge starter.
The advantages of the cartridge starter are obvious: it’s light and you can use it to self-start in out-of-the-way places where there’s no ground crew. The disadvantage is that you can run out of cartridges. (Maybe it also required extra maintenance to prevent corrosion, but I am speculating.) But the advantages go away once you have either a self-recharging compressed-air starter or an electrical starter whose battery isn’t too heavy.
I don’t know how much of this stuff will be remembered. The artifacts (“bones”) get remembered but with time a lot of the procedures and lore are inevitably lost. Could we operate an SR-71 now? We can no longer develop Kodachrome as of a few months ago. All aviation technology was created within living memory or a few years more. This won’t always be true.
In a couple of hundred years, who is going to know what any of this stuff was?
You’d be surprised. There are quite a few people out there who study and preserve old technical knowledge.
I found a website for ship model builders and historical re-enactors that had enormous amounts of technical detail such as the rigging plan for the U.S.S. Constitution at different points in its history. Each rigging plan covered over a hundred ropes.
There are many woodworking tool collectors who treasure and preserve odd tools from the past along with stories of their use. Many woodworking publications hold “what is this” challenges in which they find strange tools and challenge people to identify them.
The history of technology prior to the industrial age is difficult to puzzle out because technology was considered a matter for lower status tradesmen and not a subject worthy of upper class intellectuals who wrote the histories. E.g. Almost everything we know about medieval and early-renascence mining comes from one text De Re Metallica. Since the early-1800s technology has increasingly become higher status and viewed as more important so we have been progressively preserving more information about. For example, there are numerous studies, books and even museums dedicated to personal computers even though the technology is barely over 40 years old.
It also helps that we document everything these days. I imagine every single piece of technology used in WWII has extensive technical documentation buried in some library somewhere. I found a cache of WWII training films a few months back. What to know the startup sequence for a P-47 Thunderbolt? They’ve got a movie. Want to know how the gun sight worked? They’ve got a movie.
The technological knowledge we tend to loose is technology viewed in its day as the most humble, lowest status or so ordinary as to be unremarkable. E.g. Recipies for ink and paint from the pre-industrial age has been lost much to frustration of forgers.
I don’t know when the electric starters appeared in war planes.
The first electric starters appeared on production war plans in the mid-30s. However, they did not become common until 43-44. The German were the first to use them widely. For the allies, the most common starter early in the war was the Huck starter [video]
I didn’t realize, until I looked up the Coffman Cartridge, that they were also used in tanks with radial engines.
This thread has a lot of interesting info. I didn’t realize cartridge starters were also used on jets.
And more info.
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