P.13/36 Bomber Proposals

Here is a general arrangement drawing of the H.P.56 design, which was the original tender to P.13/36, with two Vulture engine; two prototypes of the H.P.56 were ordered in this form, together with two prototypes of the Avro Manchester, but both were completed as H.P.57 Halifaxes with the four Merlin engines.

Source: Air Pictorial, April 1955.


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Great find Stargazer,

and I want to add,in the book British Aircraft Specifications File,they mentioned only
six companies submitted a proposals,but in the fact,the Shorts and Vickers also
responded to this contest.

here is anther drawing to Hawker P13/36 proposal.


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There's been a mistake somewhere, that's the Handley-Page H.P.56, see the 3 view upthread...

It's indeed the H.P.56 Handley Page's entry to Spec P.13/36.

Checked both the Hawker and Handley Page Putnams and
RAF Bomber Command and it's aircraft vol I & II .

Poor proof reading by the Air_Britain contributors I quess...
That's right my dear Lark,

and here is Hawker proposal.


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In the main all the designs were 'big' aircraft, the exception being the Bristol design, at only 79' w/span it was the smallest of the designs.
With the initial Government delay, in funding the 'heavy bombers' seems plausible that the AM ordered the Bristol design as well, as its bigger 'brothers'. It would be used to supplement the Wellington, and replace the current twin-engine (smaller) bombers, thereby increase the potential weight bombs dropped. So, bye, bye, Blenheim, Botha, and Hampden. Beaufort retained because of its speciality, while the new Bristol aircraft had the torpedo bomber option incorporated into the finished design.

Anyone know of any artists impressions?
Given the industry's bottleneck in production capacity and Bristol's commitment to Blenheim and Beaufighter I doubt that the AM would have raised an order for a third P.13/36 contender
What 'bottleneck, I've already mentioned that the Blenheim gets cancelled, so apart from those on the factory floor, no more. Many of the parts for the new design, were parts used on various Bristol aircraft so retooling shouldn't be too complicated.

If Bristol can't cope with the work, why submit the design!?
You're not aware of the huge industry effort underway to expand production capacity, acquire tooling, recruit and train staff? Subcontracting and shadow factories were essential for the RAF expansion plans, but it was not easy.
Companies would tender to whatever was requested, leaving it to the AM to decide where priorities lay and how aircraft would be produced. Bristol's design department had spare capacity, their factories less so. It was not generally AM policy to cancel production runs unless proven essential, the time and expense of establishing production lines tended to rule that out, so your speculation that the Blenheim would get cancelled to allow for a new, and hardly ground-breaking, design to take its place is most unlikely. I would think it highly improbable that existing parts already in production would carry through into the new bomber which was to have been very different from those in production, as you would expect for an aircraft several years younger in conception.
P.13/36 OR.41 Twin-engined medium bomber for "world-wide use" introduction delayed due to production difficulties necessitating further order of Whitleys & Wellingtons
Avro Manchester (2 prototypes ordered), Handley Page H.P.56 (one prototype ordered), Hawker P.13/36 (project only), Vickers Warwick with Rolls-Royce Vulture engines

Following proposals are included.
Avro 679, Boulton Paul P.91, Bristol P.13/36, Fairey P.13/36, Handley Page HP.56, Hawker P.13/36, Short P.13/36, Vickers P.13/36,
Avro 679 Manchester, Handley Page HP.57 Halifax, Avro 683 Lancaster and Avro 684.

Vulture engine.

Avro 684.


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Does that Bristol have a 10x.303 rear turret? Or am I seeing things?

I think it's two vertically separated rows of two, so 4 total, but all visible from above rather than 2 above 2.
Given the industry's bottleneck in production capacity and Bristol's commitment to Blenheim and Beaufighter I doubt that the AM would have raised an order for a third P.13/36 contender

(As the thread has perked back into life and people will be reading it anew) Suspect you meant Beaufort and not Beaufighter there, Beaufighter is only just getting started in the drawing office when the decisions are being made on P.13/36.
The Handley Page alternative Proposal.

This was a drawing from a paper written by George Volkert, HP's chief designer and offered as an alternative to his HP.56, but it wasn't intended as an actual design. The drawing was provided to illustrate a point, that of a high speed unarmed bomber devoid of the power operated turret armament stipulated in the specification. Figures were produced that were submitted to the Air Ministry for consideration, such as a weight of 37,000lb, max speed of 380mph at 15,000ft with a wing loading of 30lb/sq ft, or 400mph at 39lb/sq ft and these were assessed and rejected as being too ambitious based on lift/drag assessments made by RAE. No drawings other than that which accompanied Volkert's paper have surfaced that might support an actual aircraft design that HP was working on.

(Figures quoted from Handley Page Aircraft since 1907, C.H. Barnes, Putnam, 1976)
You are correct, it was more a conceptual design that a true project. His paper was intended to show that without defensive armament the bomber would have performance comparable to current and planned fighters. RAE did not disagree but stressed that cleanliness of design would be critical to achieve the level of performance indicated and the AM thought that the speed margin over fighters was minimal. Its discussed in Tony Buttler's Fighters and Bombers 1935-1950 and there will be more in BSP4
From trawling through this forum I've seen, Schneiderman, that you are wanting a copy of the full document. Did you manage to locate one? I'm not sure if the RAF Museum has a copy among its HP files, might be worth checking if you haven't already.

Its discussed in Tony Buttler's Fighters and Bombers 1935-1950

I wrote an article a few years back about the development of the high speed bomber concept, incorporating Volkert's paper, the Blackburn B.28 and the Mosquito and referenced the book, of which I have a copy. A paragraph:

"One of its eager supporters was Research Director Aircraft, Capt R.N. Liptrot, who calculated that such a machine's top speed could exceed that of the Supermarine Spitfire, at that time still in prototype form. His response to Volkert's paper was deliberately provocative, designed to ensure vigorous argument. Another supporter of the idea was C-in-C Bomber Command, Sir Edgar Ludlow-Hewitt, who noted that; “...it is not an unarmed bomber that we require, but a Speed Bomber.”

Among the high level discussion within the RAF that went on over the winter of 1938/39, the Chiefs of Air Staff agreed that a formal specification should be written and prototypes built. Despite this however, the Operational Requirements department declared that the 'Speed Bomber' enjoyed no significant benefit over contemporary concepts. By August 1939, a few weeks before the outbreak of war, Ludlow-Hewitt again voiced his support for a fast bomber, insisting that it should be given the highest priority. This was effectively countered by Assistant Chief of Air Staff William Sholto Douglas, who was against the idea of an unarmed bomber, claiming that it would be countered by improvements in single-seat fighters in due course, although simultaneously he authorised construction of a prototype of an unarmed reconnaissance bomber concept under development by Blackburn Aircraft in Yorkshire."
Yes, I got a copy of Volkert's memo from a helpful friend and copies of the RAE reports from FAST. The concept of a fast unarmed bomber was being pursued by several designers at this time, supported by a few key people in the AM, such as Liptrot, and of course DH were the company that finally gained approval to proceed.
Yes, I got a copy of Volkert's memo from a helpful friend and copies of the RAE reports from FAST.
Excellent. Great wee facility at FAST. Will your research go into print?

and of course DH were the company that finally gained approval to proceed.
Took a bit of persuading some people and a needless diversion of Sholto Douglas insisting on it being fitted with a tail turret!
Excellent, more information on this is required out there. As a book or article?
I have just happened to find this excellent forum, I am trying to do some research into a model I have that appears to be a tender model produced by Hawker for the AM 13/36 requirement. I have attached pictures in the following post. I would really appreciate any further information!
Very many thanks in advance
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A fantastic acquisition! The ultimate UK project guru Tony Buttler has little to say regarding this project in BSP4 so I guess its going to be a task to locate data, maybe someone with knowledge of the archives at Brooklands could help.
Great pics! In fact I had to size the first two down 50% as it was choking the image thumbnail function.

Tony Buttler says:

Thanks Romone for an extraordinary posting. I am staggered at the excellent condition of this model, given its age. Brooklands has very little in the way of pre-1944 documents but I will ask my good friend who looks after the Hawker archive if he has any more.
Now there's a challenge, outside of my usual areas of interest but worth a dig around I think
Has any more turned up on the Shorts proposal, other than the model shown in BSP?
Has any more turned up on the Shorts proposal, other than the model shown in BSP?

May there was more Info in two sources,Aeroplane or Profile magazines ?,specially the last one.
Has any more turned up on the Shorts proposal, other than the model shown in BSP?

My dear PMN1,

from unknown source,estimated data

it was a mid-wing design,powered by two engines,had length 18m,span 22.5m and for the empty weight was 11,500 kg ?!.
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