"Jim Wilkins" <
murat...@gmail.com> wrote in message
news:sgo8h3$ph5$1...@dont-email.me...
> Excessive weight was the reason given for not deploying a developmental US
> heavy tank. They would inevitably have to cross rivers on temporary
> bridges that couldn't support their great weight. Or so I read.
More the entire system needed to upgrade, like having cranes able
to put them on and off ships and so on.
> Interestingly the success of the very fast, lightly armored M18 Hellcat
> seemed to support the decision.
>
https://en.wikipedia.org/wiki/M18_Hellcat
> "The Hellcat was the most effective U.S. tank destroyer of World War II.
> It had a higher kill to loss ratio than any other tank or tank destroyer
> fielded by U.S. forces in World War II."
The most obvious question is what is a kill and what is a loss,
how do the units prove they hit and destroyed a target and also
show which losses were to enemy tanks versus anti tank guns.
Next comes the fact the US was upgrading its vehicles.
Sherman protection and combat power related improvements in
early 1944:
The 47 degree sloped front plate, there was an increase in
thickness (2 to 2.5 inches) plus the elimination of shot traps
and the extra slope to improve protection. Thicker glacis.
Wet Stowage.
All early 1944 76mm Shermans came with superior optics, compared
to the 75mm versions, such optics had already been fitted to the M10
and M18. Then, probably during 1944, M18 production was fitted
with an even better optics system. The 76mm Sherman production
caught up with Tank Destroyer optics again in the second half of
1944 and the 75mm Sherman version, M4A3, still in production was
also fitted with similar superior sights at the same time. The first of
these 75 and 76mm Shermans arrived in Europe in the autumn of 1944.
These improvements was rated as "nearly as good as the Germans",
with the US system having a wider field of view, helping situational
awareness. Late model M36 had probably even better optics.
Now to the US Army loss reports.
Then comes how each individual army used its vehicles, for example
from 13 October 1944 onwards First army reported a loss of 93% of
average strength for the 75mm M4 and 71% for the 76mm version.
Third army (from 15 October) reported 61% and 148% respectively.
Ninth army reported 70% and 59%.
So percentage of time where there were no M4 75 and 76mm
losses, First 7%, Third 2.5%, Ninth 21%.
Percentage of time where the daily losses were 0.01 to 0.24%,
First 29%, Third 28.5%, Ninth 38%.
Percentage of time where the daily losses were 0.25 to 0.49%,
First 19%, Third 18%, Ninth 16%.
Percentage of time where the daily losses were 0.5 to 0.99%,
First 32%, Third 39%, Ninth 19%.
Percentage of time where the daily losses were 1% or more
First 13%, Third 12%, Ninth 5%.
Third army appears to have an M4 tank loss rate of 10% or more
above that of first and ninth once the initial First Army Ardennes
losses are discounted even after some Third Army Ardennes losses
are also removed. Third army clearly used it tanks more often.
The tank destroyers, the M10 and M18 were present from D-day,
the M36 from around 20 September 1944. The figures come from
the monthly report. Note these are loss rates versus the on hand
strength, not the combat unit strength
This will also bias the figures against the M10 given its average
strength remained roughly constant over the time period,
while the M18 strength started at 146, climbed to 306 in
December 1944 and was 448 in February 1945. Similarly
the September M36 strength was 170, and it climbed to
365 by January 1945 and was 826 in February. Given the
delay between arrival and issuing of vehicles you can
see how the statistics will make the M10 appear worse.
For the time period D-Day to 20 February the average M10
strength was 696 vehicles and 439 were lost, or about 63%
of the average strength, for the M18 it was average strength
around 244, with 120 losses, or about 49% of the average
strength.
For the time period 20 September 1944 to 20 February 1945
the average M10 strength decreases to 661, with 353 losses,
or around 53% of average strength, the M18 average strength
increases to 302, with 108 losses or 36% of average strength.
The M36 average strength is 358, with 72 losses, or around
20% of the average strength.
Assuming the 3 vehicle types were used in the same manner
and the strength figures are representative of front line numbers,
then the conclusions are simple. Comparing the M10 to the M18,
speed is armour, at least in ground combat when there is usually
somewhere you can move to and hide, but the M36 indicates
trumping speed is having a big gun that can make a real mess at
long range of anything that can hurt you. If Admiral Fisher was
General Fisher, he would have been much more correct it seems.
For the period 20 September 1944 to 20 February 1945 the
figures indicate for every 1% of M36 strength lost, 1.8%
of M18 and 2.7% of M10 strength was lost. Almost, but
not quite 1 to 2 to 3. While the numbers here are a guide,
and certainly overestimate the M10 vulnerability, it is
reasonable to assume that in fact the extra speed did keep
M18 losses below M10 losses, and the 90mm gun on the
M36 enabled an even lower loss figure.
A final point on the Tank destroyers, despite being listed
as in theatre on 6 June no M18 losses were recorded until
the report starting 20 July, also only 1 M10 was reported lost
before 20 June. Another point pushing up the M10 loss
rate is the January/February 1945 loss of 106 M10s, or
around 30% of the total losses from 20 September 1944.
Also around half the M36 "combat days" were in the
January/February 1945 report period, as on hand strength
went from 365 to 826 and this drives down the overall
loss rates. The effect of excluding these final month's figures
can be seen in the next paragraph and is another warning to
treat these figures as guides, not absolutes.
Now for a quick comparison between the Sherman and Tank
destroyer loss rates for the time period 20 September 1944
to 20 January 1945. For every 1% of M36 strength lost, 1.54%
of M18, 1.67% of M10 and 2% of 75mm and 76mm Sherman
strength was lost. Note the closing up of the different Tank
Destroyer loss rates. As expected the Sherman loss rates
were higher, given the different use made of it. In percentage
terms, for this four month period, 45% of M4 average strength
was lost, 38% of M10, 35% of M18 and 23% of M36.
Geoffrey Sinclair
Remove the nb for email.