Programme about Amiens Prison Raid

In article , Keith Willshaw
writes

"Emmanuel Gustin" wrote in message
...
"Dave Eadsforth" wrote in message
...

1. I have never heard of a velocity limit on aerial bombs.


Keith, Emmanuel,

Thanks for the info and comments. It strikes me that:

According to McBean & Hogden in "Bombs Away", the bombs
used in the Amiens prison raid were 500lb MC bombs, fitted
with 11 second delay fuses; dropped at very low level to skip
over the ground and hit the prison walls. The walls were
reportedly about 1m thick, hence the bombs would not easily
go through them. I suppose fairly long delays were used to
protect the bombers from the blast of their own bombs.

The 11 seconds would allow the bombs to come to complete rest before
exploding - which 1 sec or 2.5 sec probably would not.

It is not impossible that the need to "skip" the bombs over
the ground imposed flying speed restrictions, as one would
not want the bombs to break up before hitting the target.

Re. Keith's comment below about the choice of bombs - I suspect that
skipping was probably not a consideration when the bombs were designed,
so maybe a crack in the side of the casing was considered a possibility,
and perhaps the bombs had to be dropped at less than maximum airspeed.
That would make the presenter's comment a bit more sensible. But I
still just don't believe the 125 mph figure. I have just looked up the
safety airspeed for a loaded Mosquito and it looks like being around 170
kts.

Another basic concern on such attacks was leaving enough
time for the fuse to arm.

So, given the safety speed for a loaded Mossie, I suspect the speed for
the attack could not have been less than 200 mph, and at that speed a
2.5 sec delay would have placed the Mosquito 730 feet away - a distance
of under 250 yards; probably too close for comfort, so 11 secs does
indeed look far more attractive!

According to the signal sent from 2 group the bomb load
and fusing to be used was:

2 x 500lb M C Mk.IV fused T.D. 11 secs.
2 x 500lb S A P fused T.D. 11 secs.

Keith


Cheers,

Dave

--
Dave Eadsforth