British-built (Go To French)
General Information
Type Type 9400Type 9700
Function Fighter/ ReccoBomberBomber
Year 1915 1916
Crew 21
Powerplant
Type (a) Clerget 9Z
(b) Clerget 9B
Power (hp) (a) 110
(b) 130
Size
Length 7.70m
Height 3.12m
Wingspan 10.21m
Wing area 32.14m2
Weights and loads
Empty (kg) 571 to 593640597 to 627
Loaded (kg) 975 to 1,0081,0531,062 to 1,082
Wing Load (kg/m2) 30.34 to 31.3632.7633.04 to 33.66
Power load (kg/hp) 7.50 to 9.168.10 to 9.578.17 to 9.84
Speed (km/h)
at 1,981m 160 to 162161135 to 164
at 3,048m 141 to 157144129 to 159
at 4,572m 140??
Range
Normal 565km?
Flight endurance 3h45min8h
Ceiling
Ceiling (m) 4,724?3,962
Climb (min)
1,981m 9.25 to 10.8316.4512.67
3,048m 20.42 to 29.5035.0024.42 to 36.00
4,572m 41.83??
Payload (kg)
Fuel/Oil 149-168?228
Armament
Gun type (a) 1*7.7mm Vickers
(b) 1*7.7mm Lewis
1*7.7mm Vickers
Position (a) Fixed, on forward fuselage
(b) Flexible, rear cockpit
Fixed, on forward fuselage
Ammo (rpg) (a) 300
(b) 5*97
500
Salvo (kg/sec) (a, b) 0.094 each0.094
Bombs None4*11,3kg or 2*29.5kg4*29.5kg
French-built (Go To British)
General Information
Type SOP. 1A.2SOP. 1B.2SOP. 1B.1
Function Fighter/ ReccoBomberBomber
Year 1916
Crew 21
Powerplant
Type (a) Clerget 9Bc
(b) Le Rhône 9Jby
Clerget 9Bb
Power (hp) (a) 145
(b) 135
135
Size (m)
Length 7.70
Height 3.12
Wingspan 10.21
Wing area 32.14m2
Weights and loads
Empty (kg) 526?600
Loaded (kg) 926?1,096
Wing Load (kg/m2) 28.81?34.10
Power load (kg/hp) 6.39 to 6.86?8.12
Speed (km/h)
at 1,981m 159 to 167??
at 3,048m 156 to 161??
at 3,962m 150??
Range
Flight endurance 2h 15min4h 15min
Ceiling
Ceiling ?m
Climb (min)
1,981m 10.67 to 12.75??
3,048m 17.67 to 23.67??
Payload (kg)
Fuel/Oil 118?214
Armament
Gun type (a) 1*7.7mm Vickers
(b) 1*7.7mm Lewis
1*7.7mm Vickers
Position (a) Fixed, on forward fuselage
(b) Flexible, rear cockpit
Fixed, on forward fuselage
Ammo (rpg) (a) 300
(b) 5*97
500
Salvo (kg/sec) (a, b) 0.094 each0.094
Bombs None4*120mm18*120mm or 6*155mm or 12*120mm plus 2*155mm

Sopwith 1½-Strutter

36k b/w picture of a two-seat 1½-Strutter in early style Red Star markings from "Soviet Aircraft and Aviation 1917-1941" by Lennart Andersson, p.225

T

his aircraft was designed for the British Admiralty by Herbert Smith in 1915 and was the first of a long line of military aircraft to bear his signature. The somewhat peculiar (and unofficial) name of '1½-Strutter' had its origin in the unusual arrangement of the type's center section struts. The official British RNAS designations of this type were 'Type 9400' for the two-seater and 'Type 9700' for the single-seater. This aircraft was one of the few WWI types which were built in larger numbers abroad (in France and Russia) than in their country of origin.

Service introduction into the British RNAS and RFC was in spring of 1916. The RNAS planned to establish one of the first strategic bombing forces (No. 3 Wing) with this type, but because of urgent need of the RFC for additional aircraft had to deliver an appreciable number (about 80) of its newly received Strutters to this service which caused some delay to the establishment of No. 3 Wing. The Strutter was built in two- und single-seat versions and was conceived to fulfil the roles of fighter, bomber and reconnaissance aircraft. It was the first British aircraft intended to be equipped from the outset with a synchronized machine gun. Normally in RNAS machines was installed the Scarff-Dibovsky gear (designed by Warrant Officer F.W.Scarff of the British Admiralty and Lt. Cmdr. V.V.Dybovskij of the Imperial Russian Navy), and the Strutters of the RFC usually used the Vickers-Challenger device for the fixed Vickers gun. Additionally, the two-seaters carried a movable Lewis machine gun in the rear cockpit, initially on cumbersome Nieuport mounts, but later the excellent Scarff No.2 Ring Mounting was used. There were also operational armament modifications, e.g. an additional Lewis gun on the upper wing on some single-seaters. Two-seaters could be equipped with some bombs on underwing racks, but the single-seaters had an internal fuselage bomb bay, the doors of which opened under the weight of the falling bombs and were pulled shut again by rubber cords.

34k b/w picture of a single-seat 1½-Strutter, albeit in British markings from Squadron Signal's No.110 "Sopwith Fighters in Action" by P.G.Cooksley, p.17

Construction of the Strutter was the usual wooden, wire-braced box girder of that time. Most of the structure was covered with fabric, except the top decking around the cockpits (plywood) and the front fuselage (aluminum panels). An unusual feature was the trailing portion of the lower wing center section which consisted of movable panels pivoting at about one-third of their cord on a spanwise axis and so acting as air brakes. Another innovation was the tailplane which was adjustable in flight. The observer in the back cockpit had access to the elevator control cables, providing him with minimal flight controls in the case of an emergency. In the two-seater, the cockpits were relatively far apart, because the fuel tanks were located between them.

At the time of its service introduction the Strutter proved to be an effective fighter and - due to its good long-range capabilities - also a successful bombing plane, delivering some spectacular long-range bombing raids against targets in Germany. From summer of 1916 the type received more powerful 130hp Clerget engines. But the altitude performance above 3,048-3,658m of the Clerget engines was relatively poor and therefore the Strutter was not able to compete any longer with the newer German fighters from early 1917 on. Nevertheless the type served with the British forces until the end of WWI. It was also used as a home defense fighter and for anti-submarine patrols from 1917 on. The Navy also used a specially modified version ('Ship Strutter') in some numbers from carrier vessels and gun turret platforms of battleships.

According to the available sources it seems that 1,347 Strutters and Ship Strutters were built in Great Britain by nine different contractors. 196 additional machines had been ordered, but were cancelled. At least 22 aircraft were rebuilt from wreckage or spares. Production for the RFC totalled 881, for the RNAS 466 machines. Of the total British production, 947 machines were Type 9400 two-seaters, 270 examples Type 9700 single-seaters, of 86 the exact variant is uncertain and 126 from British and French production were modified into Ship Strutters. Additionally there was a number of prototypes and modifications. One source states that a minimum of 356 British-made Strutters went abroad (231 two- and 125 single-seaters). Of them Russia received at least 164 two- und 40 single-seaters (see below for details).

France had been interested in the 1½-Strutter from an early date on and had received a number of machines from Great Britain in early 1916. In the same year production of this type started in France at four companies, lasting until about April 1918. French production totalled about 4,500 aircraft, but was slow on gaining momentum. In French service the type bore the designations SOP. 1A.2 (two-seat fighter-reconnaissance), SOP. 1B.2 (two-seat bomber) and SOP. 1B.1 (single-seat bomber). French aircraft began to reach the majority of operational units at a time when this type was already outclassed, so the French experiences with the Strutter were less positive than the British ones.

17k b/w picture of a two-seat 1½-Strutter on skis in Russian markings from Profile Publications No.121 by J.M.Bruce, p.14

Besides Great Britain and France the 1½-Strutter was also used by the US Army and Navy in significant numbers. Smaller quantities went to Belgium, Romania, Japan, Latvia, Lithuania, the Netherlands, Greece and possibly Brazil. Another important user was Russia, which received a larger number of aircraft of this type from England and France from 1916 on and captured some more from the intervening Allied forces (England, France, Japan) in the fighting following the October Revolution. Additionally, the type was built in Russia itself (a last batch of about 25 machines being finished at GAZ-1 in 1922).

Numerically the 1½-Strutter was the most important Sopwith type in Russian/Soviet inventory. The total number of aircraft of this type delivered to or built in Russia (by Dux and later GAZ-1) is lacking, but the following British serials of Strutters delivered to Russia are known ('A' are from RFC contracts, 'N' numbers from RNAS):
A966A2427-A2430A6960A8318-A8324
A969A5246-A5251A6973-A6978A8327-A8331
A983-A985A5256A8141A8744-A8746
A1118-A1126A5973-A5976A8143-A8145A8748-A8749
A1131A6011A8154-A8155A8751-A8758
A1133A6015A8157-A8161A8769-A8770
A1135-A1136A6017A8175-A8182A8772-A8776
A1147A6924-A6926A8185-A8192A8791
A1511A6929-A6942A8264-A8266N5219
A1516-A1560A6949-A6951A8309-A8313N5244
A2421-A2423A6953-A6955A8316
A2425A6957-A6958

An other source lists the following additional 14 serial numbers:
A1000A1013A2383A2411
A1002A1015A2395-A2396A8204
A1010A1017-A1019A2398

The two-seat 1½ Strutter was manufactured in Russia by the Dux company of Moscow and by V.A.Lebedev of Novaya Derevna, St. Petersburg. The first Lebedev contract, dated 1st July 1917, was for 50 Sopwiths; it was followed by a later order for 140 further aircraft. The Russian-built 1½ Strutters had modified undercarriages of Russian design. Owing to a chronic lack of engines, few Russian-built 1½ Strutters entered service.

At least 34 machines of this type were taken over by the RKKVF in 1917 and until 1922 this was one of the most numerous types in the RKKVF. At the end of 1920 a total of 130 Strutters is reported to have been in service and a year later there were still 82. They served in all military districts, but most of them were assigned to the Eastern Front district, North Caucasus, Caucasus, the Ukraina, Kiev, Khar'kov, Turkestan and the 5th Army in Siberia. Most of them were equipped with the 130hp Clerget 9B, but some were also fitted with a 120hp Le Rhône. Seven Strutters were also serving with the Soviet Latvian Air Force in 1918/ 19.

The following RKKVF units are known to have operated the Sopwith 1½-Strutter:


Created for RAM March 10, 2001
by Thomas Heinz
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