The Inertial Starter on the Messerschmitt Bf 109

[schwarze-man]

Originally Posted by Snautzer

Hope you made some recordings (sound and moving) for this, i would love to see them :-))

Well, there is a lot of recordings of Black-Six that were made. Cheers

SM

[schwarze-man]

Other reasons for using a battery cart with a flat battery on an original 109 would include: supply for the ignition "buzzer" to help with the HT supply at start, power for instruments like the fuel gauge and AI, Pitot heat supply etc

Cheers!

SM

[Mr Schmitt]

Interesting reading. Attached images are the said hand starter.


Happy New Year to all.

[schwarze-man]

Many thanks for posting those images of the Bosch AL SED AR1 Anlasser Mr Schmitt!
As can be seen, this starter is the manual-only type, that was used by the wartime Bf109. The reduction ratio from the flywheel produced around 800ftlb's of torque on the 3 toothed engagement dog. You can see that this particular starter has seen some use, with the dog teeth showing some damage. Cheers

SM

[Broncazonk]

At the end of the wind-up, it looks like you had to get the handle out in a hurry or you would end up with a broken arm--the handle would continue to spin?

Video of a wind-up inertia start on a D13 @ the 5:03 - 7:00 min. mark:
https://www.youtube.com/watch?v=uf7nyTdwsHU

Video of a wind-up inertia start on a D9 @ the 23 sec. mark:
https://www.youtube.com/watch?v=4Y5LBUVS1T8

Also, the process looks exhausting. I can't image trying to start these things in the blowing snow, at 20-below zero F. on the Ost front.

Bronc

[schwarze-man]

Thanks for posting those vids Bronc.
The 109 in that first vid is a Hispano airframe with a genuine Bf109E engine and cowling and some unknown type propeller blades. I guess that they also fitted an electric energised type starter and rigged it up but, I don't think it was working correctly.
The 190 is the rebuilt genuine D-13 with the Jumo213. This should have the electrical energised starter as standard and they are using the manual back-up for most of the video as it is not working correctly.
Overall, the manual or electric inertia starter is reliable when used on a servicable aircraft.
Cold start, there is a proceedure for using the inertia starters in cold conditions. The DB605 came with oil dilution and acetylene gas cold start equipment as standard.

SM

[Mr Schmitt]

Originally Posted by schwarze-man

Many thanks for posting those images of the Bosch AL SED AR1 Anlasser Mr Schmitt!
As can be seen, this starter is the manual-only type, that was used by the wartime Bf109. The reduction ratio from the flywheel produced around 800ftlb's of torque on the 3 toothed engagement dog. You can see that this particular starter has seen some use, with the dog teeth showing some damage. Cheers

SM

Yes you are very observant. The teeth do show some damage. This is one of my spares and the one nearest to hand. Attached is a picture of the Linkeage between the starter handle and the Inertia starter for the Emil. There are slight variations in these depending on aircraft type. Note also that the body of this crank handle is primarily made of Electron and they were also made from Steel. Also you can see the slip out key of the shaft for when the engine starts so that it does not throw the starter handle and cause kick-back or worse. Note also that given this was on the Starboard side between the Cockpit and the propellers in the case of the 109 Emil, the handle is rotated anticlockwise away from the propeller blades, a forward thinking safety feature for the Ground Mechanics when starting. Kind Regards

[stephen f. polyak]

A bit more information with additional photo of starter...


https://forum.axishistory.com/viewtopic.php?t=169987

[schwarze-man]

Hi Mr Schmitt,
Yes, the manual starting handle is on the RHS of all DB powered 109's. There is normally no problem with "kick-back" on this type of starter because the inertia of the flywheel stops sudden forces being transmitted, it is always in the gear train to the starter handle and, there is a very strong slip clutch between the engagement dog and the drive to the flywheel. If the engine does kick-back while the starter is engaged, the slip clutch slips (at about 800 ft/lb!). Surprisingly, there can be enough energy still in the spinning flywheel to turn the engine again in the correct direction if the kick-back occurs with the starter turning fast. Normally, the ground crew mechanic will have removed the starter handle after winding to 90rpm and have stood clear. However, it is possible to keep winding during the start to assist the inertia flywheel and, you do see this on some film of WW2.
Cheers

SM

[Broncazonk]

Once again, the process looks exhausting and extremely dangerous. Imagine standing in the wind, on a frozen, slippery surface, at 10-degrees below zero (F) trying to hand start a cold V-12...

Plainly stated: the black men don't get enough attention or credit.

Bronc