Sopwith Triplane

[Pips]

The Sopwith Triplane has always struck me as an odd interlude in Allied fighter aeroplanes.

When it was introduced into combat in Squadron strength in February 1917 by No.1 RNAS, it was an immediate success. It could comfortably outperform both the Albatross D.III and D.V in operational ceiling, speed and climb rate; but oddly lost out in a dive. Successful pilots flying the Tripe (as it was known) were among the most successful during 1917; and included such notables as Collishaw, Dallas, Little, Minifie, Booker and Reid. In all (according to Franks excellent "Sopwith Triplane Aces of WWI") 23 pilots made ace on the Triplane, a surprisingly high percentage of pilots given that only four (4) Squadrons operated the Tripe.

Indeed the Tripe made such an impact on the Western Front that the Germans went triplane crazy; designs (mostly unsuccessful) pouring off the drawing board.

Yet despite the outstanding success of the Tripe, it was to all intents and purposes gone from the Front by November 1917. No's 8 and 9 RNAS gave theirs up around August, No. 10 in September. No.1 RNAS finally gave up the Tripe in mid November. According the Collishaw it was well overdue, as the Tripe was considered obsolescent by then. Indeed he claims that rising losses within No.1 RNAS were the result of staying with the Triplane too long. That claim is mentioned in several books on the Sopwith Triplane, not always attributable to Collishaw.

So why was the Triplane considered obsolescent by late 1917?

It can't be because of it's one gun armament in comparison to German fighters equipped with two - otherwise it would have been rated obsolescent way back in February 1917 when it was introduced.

It can't be because superior German fighters had made an appearance - the Tripe was still fighting the same Albatross D.III's and D.V's. The only new fighter to appear (in strength) was the Pfalz D.III, which wasn't a noticeable improvement. The Fokker Triplane would have been a handful, but following it's crashes it was effectively withdrawn until 1918.

Could it be because of the Sopwith Camel? While the Camel was slightly faster, it didn't climb any better, nor had the operational ceiling of the Tripe (excluding the Bentley engine Camel - which was outstanding). It did however have two guns and outstanding manoeuvrability.

Is that what made the Sopwith Triplane obsolescent?

[Alkali Jones]

Hey Pips,

I read once (somewhere...) that the trouble with the tripe was repair. Hole the fuel tank and it had to be taken to bits to repair it. It had to be taken to bits for most repairs. Someone here will know.

Dan S

[Barry Hickson]

Hi Chaps!
I read somewhere (Ospreys Triplane Aces ?) that it was extremely difficult to keep rigged & that & the fact of only one gun caused it to be replaced by the Camel.

[crankcase]

Nice synopsis, Pips!
it is impressive that a plane introduced in February would be withdrawn in November of the same year.
Who in this group has replaced a phone or a laptop in the same year as acquisition? Talk about the pace of progress!

If the Tripe was squaring off against the same types of enemy aircraft, then why did losses mount? It doesn't make sense that it would be obsolete versus the enemy, but only (as you suggest) against one's own newer aircraft.

Therefore, apart from the losses that I do not understand, high maintenance effortsand the new planes introduced both provide plausible reasons for the Tripe's withdrawal.
marc

[RAF56_Ball]

I would consder possible improvements in engines to the D.V/D.Va, maintenance issues (and rigging sure seems to be a significant issue) an improved learning curve by the Central pilots on how to defeat it (if dive, it will not catch you, or "zoom and boom"), and do not so quickly poo-poo 1 vs 2 guns. More "BB's" menas more death.
Improvements to the powerplant to carry 2 guns were likely negated by the relative weakness of the fuselage, BTW. That is why the Pup was not further upgraded (they shared the same basic fuselage structure). Since the Camel was already in the works to replace the Pup even before the Triplane IIRC, I think it was looked at as more of an interesting and effective experiment that had too many limitations.
And short lifespans in aviation usefulness are more the norm until post WW-2 I think.

[MikeMeech]

Hi

Of course a few of the final production Triplanes did have two machine guns, looking like the RAF Museum's example N5912.

Contact Patrol 115.jpg

Mike

[R Gannon]

I totally agree, first and foremost, I feel that it was the one gun issue, which led to its early demise. And this not only disadvantaged the Sop Tripe, but also the Sop Pup, Nieup 17/23/27, SPAD VII & DH5's during 1917 air combats. Whilst the last minute appearance of two guns (Collishaw used one such) would have no doubt been detrimental to performance, due to extra weight of gun and ammo.

As I read actual combat data, fire power & horse power were far more important, than the ability to out manoeuvrer, in achieving aerial victories, the latter being more of a defensive attribute. I think notions of gun pilots achieving their victories by dent of being able to out-manoeuver their opponents in dog fights, is for the most part romanticism.

And totally agree with the above, that German pilots quickly realised that is was safer to dive away, than dog fight the Sop Tripe, something they could do with near impunity, fighting as they did, over their own side. And a lot of these dive & spins away, were recorded as OOC's.

Another issue I've noticed, is the higher percentage of fatalities, in regards pilots brought down German side, than other types, suggestive of structural weakness.

As to 1 Naval's increasing losses in late 1917, I would suggest this has a lot more to do with the fact that 1 Naval, along with many of its fellow RFC squadrons, were committed to a lot of low ground attack work in support of the ground offensive. Most of its losses to the Jagdstafflen being on such low missions and not as a result of traditional higher level dogfights. Indeed this holds true for quite 25% of British fighter losses to the Jagdstafflen, from Aug 17 onwards. Whilst another 25% were stragglers or lone ducks, and only 50% fell to Jasta pilots in traditional higher level dogfights!!!!!!!!!

Cheers Russ

[Graeme]

Somewhere on this forum it was postulated that Sopwith and Fokker realised that the triplane layout was a dead-end in terms of development due to more wingtips meaning more vortices and more drag (a problem solved in modern times by upturned wingtips).

Installing more powerful engines did not generate the anticipated increase in speed due to much of the increased power being used to lift the greater weight of the power-plant and overcome the additional induced drag. So the powerful engine in a beefed-up airframe in a biplane configuration (a la Camel or Fokker DVII) gave a better performance.

Graeme

[RAF56_Ball]

There is an old "saw" that I remember being taught in ACM classes that in aerial combat that >80% of planes shot down in all wars did not see the enemy that shot them down. True or not, von Richtofen did note that "when you fill your windscreen with the enemy, all his manuevers are useless" (loosely translated).
Interesting point about the number of low altitude losses. Hmm ... Altitude is life! So is speed.

[totalspoon]

My two cents… (Prepare to be ripped off!)

If you read first hand accounts from Sopwith Pup pilots, you’ll read lots of references to it being hopeless below 15,000ft but being good above it. Below 15,000ft, the Pup’s superior manoeuvrability counted for little as the Albatros could effortlessly outclimb it and once above, make diving passes until the Pup was shot down. Above 15,000ft, the Albatros couldn’t out climb, out run or out turn the Pup.

This was because the relative output of the relevant engines at altitude. While the 80hp Le Rhone was not a particularly good high altitude engine, the pilot could adjust the fuel\air ratio to get the maximum engine performance available at any altitude. The Mercedes D.III however had a fixed fuel\air ratio optimised for low altitude. By 15,000ft, the fuel\air ratio had become so high it was hindering the engines performance, allowing it to be outperformed by less powerful rotary.

When the Triplanes arrived, they discovered, like the Pup, that the higher they went, the more they dominated the Albatros. With its much improved power\weight ratio, the tripe was about equal to the Albatros down low (though with only half the firepower) but up high it really shined. Efforts to introduce twin gun Trips were generally unsuccessful as it hurt the tripes high altitude performance though some skilled pilots, like Collingshaw, who had the skills to mix it with Albatros down low preferred it. In the famous incident where Dallas took on a huge formation of Albatros escorting two two-seaters over allied lines, he used his superior high altitude performance to get above the Germans and repeatedly dive on their formation until they broke and went for home. The Albatros at those altitudes couldn’t touch him. As long as the Triplane could outperform the Albatros at high altitude it would remain a viable fighter.

However, all this changed in second half of 1917 with the arrival of the Mercedes D.IIIa engine in frontline German fighters. While still using a fixed fuel\air ratio, this was set for a much higher altitude, hurting engine performance on the deck (where it was fuel starved) but giving my better performance up high. All of a sudden, the rotary engine fighters lost their high altitude power advantage. With the arrival of the D.IIIa, the RFC squadrons still flying the Pup found them obsolete and The RNAS squadrons with the Triplane was found them obsolescent. If rotary engines were going to continue to see frontline combat (and the British, due to huge shortages in Hisso production had no choice), then what was needed was a twin-gun rotary-powered fighter optimised for low to medium work. Luckily for the RFC, this is exactly what Sopwith had just produced, the legendary Camel.

Just My Opinion
Tim