Spitfire Question

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24 years 3 months

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Because of computer problems I´ve been off line for nearly a month now (I´m computer challenged), but now I´m back on and will start with a question.

I was watching Discovery on Friday evening, and they were running a program on the war in North Africa. In this program was a very brief shot of what looked like a tropicalized Spitfire Mk V C starting up for a mission. What caught my eye in this brief shot was a groundcrew operating something that looked a handle from an inertia starter on the lower port side of the cowling. When the engine burst into life the handle was removed, and once fully exposed, it looked even more like something from an inertia starter.

My question is, did the Spitfire ever have an inertia starter?? As far as I can remember, I´ve never seen any reference to such a device on an Spitfire.

What do you think?

Regards,
Galdri

Original post

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RE: Spitfire Question

Yes, I believe they did. I seemt o recall reading something in the last few days about it - in 'Spitfire Pilot' by David Crook. Those were MK I's. It may have been from when they escorted Churchill to France for talks before the capitulation, and found that they had no fuel (ended up with some old crap, and a few cases of Champagne) and no trolley accs.

Thats not much; can anyone expand?

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RE: Spitfire Question

Morgan & Shacklady suggest that Merlins were mostly electric start except the XII and the 32 (Engine not aircraft marks) which had Coffman.

Griffons were all Coffman.

I presume the Electric start employed some sort of flywheel? therefore an emergency handle might not have been out of the question.

Best I can do.

Moggy

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RE: Spitfire Question

Actually, it wasn't in Crooks book, it was in the diary kept by F/Sgt Tich Cloves, a pre-war regular sergeant fitter with 609 (West Riding) Squadron. He was i/c of one of the flights. I quote (with some context):

11th June. The 9 aircraft at Warmwell were detailed for a very important convoy job. None other than escorting a couple of Fleming’s full of VIPs including Mr Winston Churchill, Mr Anthony Eden and Sir John Dill who were on their way for a conference. They landed at an unknown aerodrome at Briare. Here there were no starter trolleys and no petrol.

12th June. Petrol of unknown vintage was made available at Briare for the return journey. Starting up was accomplished with Poilu's on the starting handles and some assistance from the aircraft batteries. The pilots arrived back at base, unwashed and unshaven, but full of beans – with bottles of champagne etc. This was shared out between the deserving cases – Flt-Sgts etc, who appreciated it very much.

13th June brought another important escort duty. This time escorting Mr Winston Churchill and Lord Halifax to Tours. There must have been a lot of talking going on. There was no stopping the night this time and pilots arrived back the same night. Extract from Squadron SRO’s Ser No 80:

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RE: Spitfire Question

Flemings?

Flamingos perhaps?

Moggy

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RE: Spitfire Question

Most surely a Flamingo!!;-)

Back to the Spitfire. Some of you are of the opinon that this is somekind of a inertia backup for the electric starter, a kind of APU. As far as I´m conserned an engine is either started by an inertia starter or not. It does not make sense to me to have two starter systems on one engine, if only for the extra weight. To have a hand driven generator (inertia driven) does not make a lot of sense to me either.

This is probably one of those things we will never know.

Regards,
Galdri

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RE: Spitfire Question

> It does not
>make sense to me to have two starter systems on one engine,
>if only for the extra weight. To have a hand driven
>generator (inertia driven) does not make a lot of sense to
>me either.

Nope,

I'm not suggesting two systems.

I'm suggesting that the electric system operates by using an electric motor to drive a flywheel, build up the inertia and then dump that inertia against the massive compression of the V12 and weight of the prop.

In the event of battery failure there is no reason not to have a facility to hand drive THE SAME flywheel. Every car of the period that had an electric starter also had a manual back up. (Not the same system I know, just a comment on the attitude of the time to electrics)

So simple question.

Who has a video of an early Spitfire being started?

Does it start to whine on an increasing note for a while and then the prop swings into life, or does the prop start to move as soon as the button is pushed?

Moggy

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RE: Spitfire Question

To the best of my knowledge the electric starter on Merlins was direct cranking. It was geared to the crankshaft via the reduction gearing and the coupling was engaged by an electric solenoid.

The Coffman cartridge starters were fitted at the same position driving the same gears but via a different coupling. When the cartridge was fired the action of a piston pushed the coupling to engage it and when pressure was released in the starter it disengaged.

In neither case was a fly-wheel of any kind involved.

It is possible and in the light of this discussion probable, that there was a backup system of manually cranking the engine.

I quote from Snapper's post:

> Starting up was accomplished with Poilu's on the starting handles and some assistance from the aircraft batteries.

This clearly indicate no inertia fly-wheel support!
The question is at which position did the crankhandle connect to the engine? It could be connected to the rear via the supercharger drive but I don´t know. This position would keep the personnel clear of the propeller though ......

The german starters were electric inertia starters which means that an electric motor spun the fly-wheel and at sufficient RPM the pilot manually engaged a clutch to connect to the crankshaft. When operating the clutch the elctric motor had been shut off.
These starters had a manually cranking backup, as a matter of fact they didn´t have the convenience of an electric motor in the early days of its development.

HTH,
Christer

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First post for me after lurking for a few weeks!
After reading the original message I began to read Alec Lumsden's 'British Piston Aero Engines and their aircraft'
In a short article on starting methods there is a head on photo of a Hurricane with a crank handle sticking out of each side of the lower engine cowling. The caption says 'The two handed starting handles of a Merlin II on a Hurricane I' the article mentions that starting handles were often connected by an inertia system but dosn't discribe the Merlin system! I believe that the Merlin II was only fitted to Spitfire Is.

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And come to think of it I can recall a well known shot of some erks hand cranking a Hurri I fitted with a Watts two blader in '39 ish so there must've been some sort of inertia system fitted to some of the early Merlins which were also used in the early MKI spits.

Tom ;)

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Posts: 359

It becomes increasingly clear that I should stop talking from memory.
It´s the Griffon that has the cartridge starter engaging the reduction gearing.
The drives on the Griffon, compared to the Merlin, were shifted from the rear of the engine to the front in order to reduce torsional vibration transferred from the crankshaft.

I have on the desk in front of me "ROLLS-ROYCE PISTON AERO ENGINES - a designer remembers" in the RRHT series.

Figures #61 and #62 show the Merlin II starter system gear drive.
The text says - electric motor input via shaft N - hand starter drive via shaft R including the inclined roller freewheel.
I don´t know exactly what is meant by the inclined roller freewheel but I think that when the engine starts and turns the drive quicker than the hand crank it disengages.
There´s no mention of a flywheel.

I know it´s not the specific engine in question but anyway ......
Figure #67 shows the Merlin XX-series geartrain.
The electric motor is vertically mounted and it engages at the rear of the engine between the crankshaft and the supercharger drive.
There´s a hand starter shaft on the startboard side of the engine engaging the same geartrain.
There´s no flywheel.

HTH,
Christer

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24 years 3 months

Posts: 1,324

Finally I´m back on line, it was not very easy for sombody as computer challenged as I´m:D

Anyway, we seem to be getting somewhere with this Spitfire starting thing. Now we know that the early Merlins had manual start option, via a starting handle. But how about the Merlin 45´s as installed in the Mk.V. I know it was basically the same engine, but in your Merlin books, is there any mention of such a system on the 45's?

Regards,
Galdri

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Posts: 4,964

Here we are, from the horses mouth so to speak. My 83 year old ex-auxiliary groundcrew friend (Spit squadron from 1938 - 40, then all over the place) says the following:

"Spitfires never ever had inertia starters, it was either a trolley ack --not available in France-- or put the cranked handle in and start winding , praying that the pilot knew what he was doing ."

(The France bit again being a reference I made to the Poilu's etc"