Lawrence Dillard wrote:

"John Mullen" wrote in message
...
"John Halliwell" wrote in message
...
In article , John Keeney
writes
Curious, the "booms" (I note the plural form) were anticipated before
anyone flew Mach 1+?
While I suppose they would be predictable, I'ld be kind of surprised
that anyone had. Was there experience with unmanned missiles or
projectiles to showed it?

According to many reports from London and thereabouts during the latterly
months of the WWI Europe, the arrival of the V-2 was announced by its
exploding warhead, followed shortly thereafter by strange noises
(associated, presumably, with the missile's having passed through mach 1).
Assuming these reports were accurate, these would have given rise to an
expectation of an audible "boom" as an object of considerable mass (say, far
more so than a bullet) exceeded mach 1.

I had a friend, now late, who served in N Africa and in Sicily; he related
on a few occasions when I could get him to talk about his experiences that
when the Germans opened fire (but "over") on his formation with their 77mm
and 88mm cannon,

snip

I'd sure like to know where the "77mm" stuff started. I've seen this mentioned
in similar accounts, especially in the early war, but the Germans didn't have
'77s'. They used various 75mm guns, mainly in tanks and SPs although there were
some leftover, modernised WW1 75s (7.5cm FK16(n.A); the 7.5cm FK18, developed in
1930-31 and produced up to 1938; and the 7.5cm FK38,144 of which were acquired
from a Brazilian order. These tended to be issued to low-grade, static
formations. There was also a 75mm infantry gun, the 7.5cm le IG18, developed
from 1927 on. Standard light howitzer was the 10.5cm leichte Feld-Haubitze 18
(le FH18), introduced in 1935.

The V-2 was supersonic as it came down, so it would explode first then the sonic
boom would be heard. Whether this was identifiable above the sound of the
warhead explosion itself, I couldn't say. Probably not by the average
bystander.

Guy