High speed unarmed medium/heavy bomber

Started by wuzak, October 01, 2013, 11:01:01 PM

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wuzak

In 1937 Handley Page's chief designer, George Volkert, wrote a paper on bombing practice and theory in which he discussed, and promoted, the idea of an unarmed high speed bomber. He argued that its performance would be superior for less cost in a smaller and lighter airframe.

In the paper he set out the parameters of such an aircraft, using the requirements of Specification P.13/36. Liek his original P.13/36 design, the HP.56, and its competitor, the Avro Manchester, this aircraft was to be powered by two Rolls-Royce Vultures. A top speed of 380mph with an 8000lb bomb load was projected.

This discussion paper did not result in any new projects or specifications at the time.

But what if Volkert were to revisit the concept when the Halifax (HP.57) was entering production? Around 1940/41 - about that time the Mosquito prototype was being built and tested.

My concept for the new high speed unarmed bomber (let's call it the Victor I) is:

  • Powered by 4 x Merlin XXs (like the Halifax)
  • The engines will be mounted in pairs - push pull style
  • The wing will be a gull wing style - see the Dornier Do 26 for what I am thinking.
  • The fuselage will be circular in section.
  • The crew will be comprised of 4 - pilot, engineer, bombadier and navigator. Maybe the last two could be combined for a 3 man crew.
  • The crew would be housed in a pressurised cabin in the front of the fuselage.
  • The bomb bay arrangement of the Halifax limited its flexibility. Having seen the Manchester/Lancaster bomb bay, the new HSB has a longer bomb bay.
  • The normal bomb load would be 12,000lb.

Only the original prototype flies in Mk I form. The Mk II uses 60-series Merlins in place of the XXs, for improved performance and greater high altitude capability.
The Mk III would use Griffon IIs.
The Mk IV uses Griffon 60-series engines, and is the ultimate war time version.

PR versions of these are, of course, built. These carry loads of cameras, film and fuel. They can operate well beyond the range of PR Spits and Mossies.

The Victor IV would be used by 9 Squadron to carry their tallboys. 617 stick with their Lancs, and are the only ones to use the Grand Slam, so 9 continue to use the tallboy, but discover that they can carry two each!

I have done a couple of sketches, but I won't be able to upload them for a few days.

What are your thoughts? How would you go about a High Speed unarmed medium/heavy bomber?

The Rat

Quote from: wuzak on October 01, 2013, 11:01:01 PMWhat are your thoughts? How would you go about a High Speed unarmed medium/heavy bomber?

I would make provisions for defensive weaponry on later versions, because sooner or later the Luftwaffe would catch up.  ;)
"My mind is a raging torrent, flooded with rivulets of thought, cascading into a waterfall of creative alternatives." Hedley Lamarr, Blazing Saddles

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wuzak

Quote from: The Rat on October 02, 2013, 04:56:21 AM
Quote from: wuzak on October 01, 2013, 11:01:01 PMWhat are your thoughts? How would you go about a High Speed unarmed medium/heavy bomber?

I would make provisions for defensive weaponry on later versions, because sooner or later the Luftwaffe would catch up.  ;)

Or just add some jets to speed up the bomber?

kitnut617

#3
Quote from: wuzak on October 01, 2013, 11:01:01 PM
What are your thoughts? How would you go about a High Speed unarmed medium/heavy bomber?

De Havilland DH.101 --- this was a project along these lines. It was supposed to be able to carry 8000 lbs internally with a further 1000 lb under each wing and fly at near 440 mph at high altitude (35,000 ft and higher).  I think Dave is right though, some sort of provision for protection should be thought about, in the Sharp/Bowyer book on the Mosquito is says that during the last few months of the European stage of the was, PR Mosquitos (which had operated just about un-opposed through most of their service) suddenly started not returning.  It wasn't until a couple of survivors reported of being attacked by jets that all was revealed.

Basically it was a scaled up Mosquito, about 1.2 time bigger and powered by two, three-speed, two stage Napier Sabres of about 3000 hp each.  I'm in the process of building one but it will be almost totally scratch-built which is ok because as I said it was basically a big mosquito but there's enough of it which isn't.  To make a 1/72 scale model you need a 1/60 scale Mosquito to rob parts from, but there isn't a Mosquito in this scale ---  

About the only thing in common is the canopy.

Side profile of it:


A comparison of the DH.98 and DH.101:






If I'm not building models, I'm out riding my dirtbike

NARSES2

It's an interesting idea Wuzak and I to would go along with the idea of some defensive armament on latter variants. In barbettes, so remote controlled ?
Do not condemn the judgement of another because it differs from your own. You may both be wrong.

wuzak

Quote from: NARSES2 on October 02, 2013, 07:29:42 AM
It's an interesting idea Wuzak and I to would go along with the idea of some defensive armament on latter variants. In barbettes, so remote controlled ?

I did, on one of my sketches, have a rear facing barbette on the upper fuselage.

NARSES2

Do not condemn the judgement of another because it differs from your own. You may both be wrong.

kitnut617

Quote from: wuzak on October 02, 2013, 07:35:46 AM
Quote from: NARSES2 on October 02, 2013, 07:29:42 AM
It's an interesting idea Wuzak and I to would go along with the idea of some defensive armament on latter variants. In barbettes, so remote controlled ?

I did, on one of my sketches, have a rear facing barbette on the upper fuselage.

The high speed, unarmed bomber concept was originally for a high altitude too, I would have the barbette on the underside.  For an upgraded version of the DH.101 I'm planning, it would have even more powerful engines (some Sabre VII's were bench tested to 5500 hp) and carry a Tallboy bomb so it could be dropped at the altitude Barnes Wallis designed it for.  I'm planning having a A-26 Intruder style remote turret under the fuselage and just behind the bomb bay.

Here's an interesting pics you might want to consider, 20mm remote turrets:

If I'm not building models, I'm out riding my dirtbike

PR19_Kit

What's going on with the tail turret on that Lanc Robert? It looks very weird.....
Kit's Rule 1 ) Any aircraft can be improved by fitting longer wings, and/or a longer fuselage
Kit's Rule 2) The backstory can always be changed to suit the model

...and I'm not a closeted 'Take That' fan, I'm a REAL fan! :)

Regards
Kit

kitnut617

It's not a turret Kit, more like the rear end of a Shackleton.  The gunner sat there and operated the two remote turrets, pretty much the same as the Windsor set-up
If I'm not building models, I'm out riding my dirtbike

jcf

Sounds good, except for the push-pull tandem engines, it's not an efficient
layout. The rear propeller effectiveness is diminished by the slipstream of
the forward prop, not good for a big, high-speed aircraft. The effect was
less pronounced on the Do 335, but only because the props were at
opposite ends of the aircraft and in different planes, the aft was higher
than the forward.

Why not keep the engine layout, but have the pair of engines driving tractor contra-props?
Have each engine drive one half of the prop ala the XB-42 and the Fairey Gannet,
even have the provision to throttle down, or shut-off, one of each pair to increase
endurance.

Here's a page on the XB-42 prop system showing what I mean:
http://www.enginehistory.org/Propellers/Curtiss/XB-42Prop.shtml



TallEng

How about a Lancaster, with Merlin 85's, clipped wings, remote turrets from that picture
(Using a periscope sighting system)
And the "speed" fairings nose and tail from the Lancastarian?
That ought to look like it would be fast :thumbsup:
I expect Roy Chadwick would be able to add some lightness to the Airframe....
The Lancaster B.VI (fitted with Merlin 85's) was allegedly good for 300mph and 28,500ft
So with a little bit of effort, a bit more speed and height ought to be possible?
And perhaps the concept would be easier as its a development of an proven airframe
As against a new unproven one.

Regards
Keith
The British have raised their security level from "Miffed" to "Peeved". Soon though, security levels may be raised yet again to "Irritated" or even "A Bit Cross". Londoners have not been "A Bit Cross" since the Blitz in 1940 when tea supplies ran out for three weeks

Gondor

Quote from: kitnut617 on October 02, 2013, 07:55:04 AM

Here's an interesting pics you might want to consider, 20mm remote turrets:




That is a photograph of Lancaster LL780G fitted with Boulton Paul twin cannon barbette defence system in 1944. The system used Amplidyne controllers through a computer which calculated deflection and range. The system also incorporated a radar blind tracking unit.

Information from British Aircraft Armament Vol 1 by R.Wallace Clarke

Gondor
My Ability to Imagine is only exceeded by my Imagined Abilities

Gondor's Modelling Rule Number Three: Everything will fit perfectly untill you apply glue...

I know it's in a book I have around here somewhere....

wuzak

Quote from: joncarrfarrelly on October 02, 2013, 01:11:27 PM
Sounds good, except for the push-pull tandem engines, it's not an efficient
layout. The rear propeller effectiveness is diminished by the slipstream of
the forward prop, not good for a big, high-speed aircraft. The effect was
less pronounced on the Do 335, but only because the props were at
opposite ends of the aircraft and in different planes, the aft was higher
than the forward.

Why not keep the engine layout, but have the pair of engines driving tractor contra-props?
Have each engine drive one half of the prop ala the XB-42 and the Fairey Gannet,
even have the provision to throttle down, or shut-off, one of each pair to increase
endurance.

Here's a page on the XB-42 prop system showing what I mean:
http://www.enginehistory.org/Propellers/Curtiss/XB-42Prop.shtml

I am not sure how much difference in efficiency between contra-props and the tandem push-pull arrangement.

The engines could be offset, like the Do 335, but I think that would make it worse - it worked on the Do 335 because of the distance between the props (~12-13m).

On this arrangement I would envisage ~5-6m between the props.


Using the push-pull arrangement has its advantages:

  • No need for extension shafts - the rear engine would need an extension shaft to drive its prop.
  • Smaller frontal cross-section - with Merlins or Griffons the drive shaft would have to pass along side the forward engine's crank case (In the case of projects with DB engines, like the Dornier P.252, the drive shaft can pass through the vee where a cannon is often mounted).
  • Lighter - extension shafts are heavier due to the torque they have to transmit.
  • Use of standard engines - standard Merlins or Griffons would be used, no need for specials with extension shafts an remote gearboxes.

Note that neither the XB-42 or the Fairey Gannet had tandem engines - their engines were mounted side by side.

wuzak

Quote from: TallEng on October 02, 2013, 01:34:40 PM
How about a Lancaster, with Merlin 85's, clipped wings, remote turrets from that picture
(Using a periscope sighting system)
And the "speed" fairings nose and tail from the Lancastarian?
That ought to look like it would be fast :thumbsup:
I expect Roy Chadwick would be able to add some lightness to the Airframe....
The Lancaster B.VI (fitted with Merlin 85's) was allegedly good for 300mph and 28,500ft
So with a little bit of effort, a bit more speed and height ought to be possible?
And perhaps the concept would be easier as its a development of an proven airframe
As against a new unproven one.

Regards
Keith

The improvement in the Lancaster airframe would not be as good as what is possible with an all-new airframe.

The Lancaster VI did, indeed, have higher performance and, probably more importantly, a higher ceiling. But not that much better.

The Lancastrian transport version of the Lancaster was used as a test bed for a number of different engines and engine types. My understanding is that it topped out at around 400mph with a pair of Armstrong Siddeley Sapphires strapped under its wings.