SE5a armament?

It strikes me as odd that the SE5/SE5a series retained its mixed overhead-Lewis/synchronized-Vickers armament throughout its WW1 service. Why was a dual synchronized Vickers armament not installed? Was the "pull-up" feature of the Lewis considered especially important?

Byron

[Billy_Bishop]

I have read that some late model SE-5a's did have twin Vickers.

I believe however, the reason for the mixed type was due to some distrust in interrupter gear. The idea being, if a pilot noticed in time that the interrupter wasn't working (and this would be obvious from the change in rate of fire) that providing he stopped using the Vickers soon enough to not damage his prop, he would not be defenseless due to having the Wing mounted Lewis.

Of course, I could be wrong.

VBR,

Al Lowe

Al,

Your theory is plausible. Perhaps it had something to do with the SE5 being the first English non-rotary engined fighter (TTBOMK) to have been fitted with interruptor gear. And they apparently did suffer initial teething troubles.

Yet, I have seen no data to suggest that SPADs suffered from this problem, although they employed the same engine/interruptor combo.

Interesting little mystery.


Byron

[PeterL]

Al,I think those twin Vickers SE's were probably U.S. (Eberhart?) built.Your theory on the whys and wherefors of the composite armament works fine for me, but was there another advantage? Did I read somewhere that the Lewis had a higher rate of fire?

Peter L

Byron: I wonder if it wasn't a simple reluctance to change. The top wing configuration had worked for Ball et al.
DD

[Terry_Crisp]

There was also the very practical advantage of being able to fire directly upwards a la Ball. This was by no means an uncommon practice and by all accounts very effective.
Hth,
T.

In addition to the aforementioned advantages of the Lewis' uninterrupted rate of fire and ability to angle the gun, I think the fact that the S.E.'s cockpit was not designed for two guns is a factor. Photos I've seen of the multiple-gun installation looked very cramped indeed. The single Vickers was angled slighty up and fired between the banks of the V-8's cylinders, did it not? Adding a second gun was not easy.

[Barrett]

If you sit in an SE-5 and then sit in a Nieuport 28 you realize what they have in common: too narrow a fuselage to support side by side MGs with attendant ammo cans, mounts, etc. That's why the "shelf" was added to the port side of the 28.

[Dan_San_Abbott]

Gentlemen:
The S.E.5/S.E.5a fuselage was 28" wide overall. The interior width was reduced by the width of the longerons, 1¼ x 2= 2.5" so the interior width is 25.5", a somewhat confined space. The Vickers machine gun was set at + 5º and Lewis machine gun was set to converge at 250 yards. Ate angle of incidence was + 5º . With the tailplane trim set at +5º the aircraft at zero climb and in level flight, flew -5º nose down. The S.E.5/5a use the Constantinesc hydraulic impulse system as a synchronizer system. It had a lot of problems with maintaining proper system pressure.
The SPAD VII and XIII used a Marc Birkigt designed a mechanical linkage synchronizing system. He was the designer of the Hispano Suiza engines. In my estimation the best and finest engine to come out of WW1. The world beaters that came later, their wet sleeve monoblock designs can be traced to the Hisso!
I have often wondered how the S.E.5a would have done with the 300HP Hispano-Suiza H, 150mph?
Blue skies,
Dan-San Abbott

[stephen]

I hear that British fighter specs actually dictated one Vickers and one Lewis per aircraft, and that the SE configuration was by specific design. Although the Lewis did have a higher rate of fire and Ball occasionally pulled a neat trick against two seaters, the primary reason was distrust of the still-new (for the Allies) synchronization gear. By the time the Constantinesco gear came out failures were rare, and most of the pilots I knew ( George Vaughn in particular) thought the Lewis was pretty worthless. Some even said it wasn't worth reloading once the first drum ran out. I don't know if the SE had the capacity for twin Vickers, but you have to look at things the way they did then... when the synchro gear was a new and fragile animal for a service that had depended on Lewis guns for two years.