In message
Post by Rich RostromPost by davidUnless we assume resources being waved out of thin air, these airmobiles
will use up resources that were, OTL, being used elsewhere. Since two of
the major bottlenecks on the Germans at this time are aero engines and
pilots. These can only come at the expense of other flying stuff, and
the Luftwaffe is already monstrously overstretched without adding to its
workload.
The assumption of the thread was: WI helicopters
had been developed before WW II and all the major
powers had significant numbers of them.
Yes, helicopters would consume resources that OTL
would be used elsewhere. This would be true for
all other powers that had them. British helicopter
development would cut into RAF bomber and fighter
deployment, for instance - unless one assumes that
Germany and only Germany was resource-limited.
Only if the UK is adopting them in large numbers. What does the UK use
helicopters for? I can see them replacing floatplanes on ships for
spotting and scouting (and once the war kicks off, replacing Y gun with
a helipad starts looking good for destroyers). Lacking a mission,
though, the helicopter ends up in the same niche as the autogyro.
In Germany, the notion of heliborne assault may take root as a superior
option to gliders and parachutes: but why is the UK acquiring a large
fleet of helicopters to the detriment of, for example, Fighter Command?
Post by Rich RostromUnless one concludes that helicopters were inferior
to any other use of the related resources, it seems
very likely that all powers would invest in them.
Only if there's a mission for them to fill.
Post by Rich RostromAlso bear in mind that airmobile infantry would
largely replace some other resource hungry elements,
such as glider and parachute troops.
Helicopters don't exactly replace gliders: you can make gliders out of
wood, while helicopters need aluminium, aero-engines and high-octane
fuel. Higher training and maintenance burdens, too. You do gain a lot
more flexibility, but it's not a simple swap.
Post by Rich RostromOTL the Germans were way, way ahead of the rest
of the world in using glider and parachute troops.
Well, apart from the Soviets...
Post by Rich RostromISTM that they would be similarly expert with
airmobiles, and that their capabilities would be
a significant surprise to the Allies.
The threat of airborne attack was widespread by the time France fell
(cue cartoon of a golfer snapping at a group of heavily-armed
Fallschirmjagers "Would you kindly stop rustling those parachutes?" as
he lines up a tricky putt)
However, the Germans actually had only five parachute battalions in OTL,
and they were reconstituting and recovering after suffering significant
losses: they'd been committed in Holland, France, Denmark and Norway and
had lost men and equipment (and Student himself had been badly wounded)
The Wehrmacht airborne force was a nominal 25,000, but only 6,000 or so
were trained parachutists (and how many men were actually assigned to
the units, as opposed to the nominal roll, is a good question; as is the
cohesion and equipment of the units after detachments had been sent out
to assorted hotspots).
Going heliborne reduces the demand for parachutes and skilled jumpers,
which was handy since silk was in severely short supply, but means
you've got to provide the helicopters.
The actual inventory of air transport available in OTL was 1,000 Ju-52s
(serviceability under 75%) and only 150 gliders.
Post by Rich Rostrom_However_: ISTM that airmobiles, which would be much more
effective than the same weight of paras,
Why? You're still sharply limited in what you can lift, still need a
clear LZ, still have to form up and move to the objective.
Post by Rich Rostromprobably could
take a port where follow-on forces could land. Difficult,
but barely doable. Most importantly, doable in June when
the British army was most disorganized, disarmed, and
demoralized.
Trouble is, so is the Kriegsmarine, and Fighter Command hasn't been
chewed down.
The seaward side of the operation is going to struggle for all the usual
reasons (the Kriegsmarine are badly outnumbered even by the RN
quick-reaction force, let alone the main force which can be in the
Channel within 24 hours.)
The air bridge is going to be highly vulnerable: laden helicopters die
quickly when met by fighters.
Post by Rich RostromThis would be because (ISTM) an airmobile move across the
Channel would not be fundamentally different from any other
airmobile move 30-50 km out. It would not require the same
degree of specific planning as an airborne op or the
improvisation needed for a seaborne op, which the Germaans
had not anticipated. It would be an exercise of a capability
they already have.
In isolation, yes. However, protecting the air bridge and getting the
necessary seaward reinforcements and resupply there remains a serious
problem. Having seized the port, you need to bring across enough troops
to defeat the 29 divisions still at home in Britain together with their
supplies and equipment
Otherwise, all you've achieved is to make a nasty mess in (for example)
Folkestone, which ends with the survivors of your elite airborne troops
being marched into captivity: meanwhile the wrecked helicopters are
melted down into Spitfires. Fighter Command licks its wounds and the RAF
and Navy argue fiercely over who saved the day.
Post by Rich RostromAnother point: ISTM that Fighter Command's bases in Kent
and Sussex would be vulnerable to heliborne commando raids.
True to an extent, but there are a number of bases and German
intelligence was very poor (especially in the timeframe you're looking
at): as it was they wasted a lot of time, fuel and ordnance on training
and Coastal Command fields.
Remember, they don't have that many air-assault troops, nor helicopters:
and helicopters both show up on radar, and because of the speed
differential are rather hard to escort.
Post by Rich RostromAgain, bear in mind the surprise factor: the Germans are
using a new mode of warfare; it would take time for the
British to adapt to it, and in the first round it could
be devastating.
But only if there's a way to follow up the gains thus made.
Trouble is, the "surprise" argument only works if the heliborne assault
really is a new concept: which means it wasn't used in Holland, or
France, or anywhere else previously (so how is Eben Emael being taken?)
and isn't given away by raids on Manston.
Post by Rich RostromMen and supplies could come by helo at night.
This is a difficult evolution even today, with trained crews using night
vision goggles. Falklands experience was that night helicopter
operations were demanding even for NVG-equipped singletons: the notion
of flying a fleet of lightless helicopters across the Channel, seeking a
landing zone in the blackout (of course, it could be lit up to help both
the German pilots and the British artillery spotters...) while
nightfighters flit about, is not comforting if you're depending on them
for reinforcement, resupply and medevac.
Post by Rich RostromVehicles and heavy equipment must come by water; but the
Germans don't have to control the Channel, they only need
to disrupt British control enough for some fast transports
to sneak through at night.
MI14 did some detailed analysis of the logistics involved, and tried to
err on the side of the Germans. Assuming Folkestone to be captured
intact, without the blockships in place or the quaysides being fouled,
then an optimistic 150 tons per day could be unloaded for the first
week, rising to 600 tons per day after that. (If Dover could also be
taken, then it could manage 800 tons per day after the first week).
This tonnage was insufficient to supply even two British infantry
divisions: even assuming the Germans fought with tighter belts and
shorter rations, MI14 couldn't get their supply requirements down below
300 tons per division per day. (Note that this is to supply a division
that's made it ashore: to ship them in would have to be done over the
same quays and within the same limits)
The bad news was, UK Home Command could call on 29 divisions plus eight
independent brigades. The worse news was that, as well as assuming the
ports to be almost magically falling into German hands, MI14 granted the
enemy control of the seas and assumed the worst case of no RN
intervention.
Post by Rich RostromThe Channel Fleet would be
pretty beat up at that moment, coming off Dunkirk.
Thirty-six destroyers in four flotillas (the Humber, Harwich, Sheerness
and Dover) on dedicated anti-invasion duty, with the Auxiliary Patrol
having 400 armed trawlers and drifters and 700 other scouting vessels
available. The RN met its destroyer losses off Dunkirk by depleting the
Western Approaches, rather than weakening the defence against invasion:
and the force at Scapa demonstrated its capability to be in the Channel
within 24 hours of notice to steam.
Meanwhile, the Kriegsmarine was in a really sorry shape. Scharnhorst and
Gneisenau were in dock with torpedo damage: only two cruisers were fit
for duty, and the numbers of operational destroyers could be counted
without running out of fingers. Not good odds to try to lift multiple
divisions across the Channel into a contested port.
Post by Rich RostromThe whole proposition is still odds on, no question.
But it seems a lot less improbable with airmobile
forces (IMO).
Seizing the port and preventing its Cherbourg-style demolition is made
more likely: but then what?
--
He thinks too much: such men are dangerous.
Julius Caesar I:2
Paul J. Adam MainBox<at>jrwlynch[dot]demon{dot}co(.)uk