How many SE5a Hispano vs. Wolseley?

[terrymayfield]

Maybe someone knows - how many SE5a 200hp Hispano-Suiza versus 200hp Wolseley Viper's were produced DURING the war? I have never seen any figures other than some comments around 800 for the HS and the rest Vipers begining in the Spring of 1918. I also note that most comments claim a production of over 5000 SE5a's, but I have seen figures that claim only 2,700 were produced DURING the war. Can anyone clarify?

Terry

[TomVrille]

Greetings Terry, and welcome to the forum

It will take a bit of digging to get the complete picture you are looking for, but I will make a few introductory remarks. If you wish to pursue the question in depth, I recommend starting with a review of The S.E.5 File by Sturtivant and Page. This is the reference I used to compile my introductory comments, and has the most detailed breakdown I know of for production statistics of the S.E.5a.

To begin with, a total of 77 S.E.5s were orderered from the Royal Aircraft Factory. Of these 77 aircraft, 7 were equipped with the 200 hp Hispano-Suiza to bring them up to S.E.5a standard. An additional 8 aircraft were re-engined with the 200hp Hisso at the depot level, but these were not produced to S.E.5a specifications.

The rebuild process had a significant influence on the ratio of Hispano- to Viper-engined S.E.5as in service at any given time, since it became common practice to replace the HS engine with the Viper by mid-1918.

The first production contract to the full S.E.5a standard was with Martinsyde Ltd. This contract for 200 aircraft was placed on 1 February 1917. A second contract for 200 aircraft was placed with Vickers Ltd five days later. The 200hp Hispano-Suiza engine was the nominal standard for both of these contracts, but several exceptions were made during production. In the case of Martinsyde, 13 aircraft were equipped with the Viper, and 3 aircraft were built with 180hp engines. At Vickers, where production was completed some three months earlier than at Martinsyde, 4 aircraft were built with the Viper.

The first installation of the Viper engine was under a contract for 50 aircraft with the Royal Aircraft Factory. This aircraft was delivered to the Test Squadron at Martlesham Heath on 25 August 1917.

Looking at the summary of production contracts that were actually fulfilled, as listed in the reference noted above, a total of 5148 S.E.5as were built, under 31 separate contracts. From the brief overview of the first two contracts presented above, this figure drops by three aircraft, since those aircraft built with the 180hp engines were not up to S.E.5a specification. But, if the 7 aircraft built to S.E.5a standard under the S.E.5 contracts are taken into account, total S.E.5a production rises back to 5152.

So much for introductory remarks!

[terrymayfield]

TomVrille;
Thank you for your response and keep going, going, going on!

Terry

[TomVrille]

Originally Posted by terrymayfield

....... keep going, going, going on!

I was thinking of this thread more as a relay race than a marathon. I'm ready to pass the baton!

TV

[Dan_San_Abbott]

terrymayfield:
Some time ago, I did a study of S.E.5a contracts to determine what engine went into specific contractors.
I have gone nuts trying to find the study to give you the specific engine used in what serial number batch. The problem is, I can't find the study, so I'll try something else.
For the most part The French geared Hisso was used in most of the contracts up through 1918. For example, Austin Motor was building S.E.5a for the RAF with the geared engine while building direct drive Wolseley Viper for the U.S. Service in late 1918.
Another example is the engines in store with the RAF on 31 October 1918: French Geared Hisso, 2173 engines; Wolseley Viper, 1263. The engines in storage reflect the ratio of the S.E.5a machines in service. The ratio is for every Wolseley Viper, there was 1.78 French Hisso engines. When I find the study, I will post it.
Blue skies,
Dan-San

[Craig]

Originally Posted by TomVrille

Looking at the summary of production contracts that were actually fulfilled, as listed in the reference noted above, a total of 5148 S.E.5as were built, under 31 separate contracts.

Was there any noted difference in quality from these 31 contractors?

[TomVrille]

Originally Posted by Craig

Was there any noted difference in quality from these 31 contractors?

There were six different contractors who filled production contracts for the S.E.5a. These were the Royal Aircraft Factory, Martinsyde Ltd, Vickers Ltd, the Austin Motor Co Ltd, the Air Navigation Co Ltd, and Wolseley Motors Ltd.

The 31 contracted production totals for these contractors were:
Royal Aircaft Factory - 173
Martinsyde Ltd - 550
Vickers Ltd - 2165
Austin Motor Co Ltd - 1550
Air Navigation Co Ltd - 337
Wolseley Motors Ltd - 431

This total contracted production adds up to 5206 aircraft. The difference from the summary production total of 5148 cited in The S.E.5 File perhaps reflects the number of aircraft which, for whatever reason, were not up to S.E.5a standard. If this is so, the numerical analysis of my previous post, based only on two contracts, should be dismissed.

There were evident differences in quality among the various production batches, but in most cases, these were due to variations in the quality of the engines installed.