Geschützwagen IVb für 10.5 cm le.F.H.1811 (Sf.) (Sd.Kfz.165/1)Sd.Kfz. 165/1 10,5-cm le.FH. 18/1 (Sf) auf Geschützwagen IV b
Krupp presented the conceptual design of Germany's first true self-propelled artillery piece to Wa Prüf 6 on 14 September 1939. Wa Prüf agreed with the layout of an engine mounted in the rear because installing an engine under the gun mount had large disadvantages.
As originally envisioned, the le.F.H.18 ( light filed howitzer) mounting was very limited in traverse. A fully traversable turret wasn't desired because it would too closely resemble the design for a 10.5 cm turret mounted on a Pz.Kpfw.IV chassis which hadn't been accepted for series production. Therefore the final turret design was limited in traverse (70 degree arc) and open-topped, with the sides slanted downward toward the rear.
A trial series of two Pz.Sfl.IVb (Fgst.Nr.Vl and V2) was ordered. Both of these Versuchswagen 1.F.H.18 (gp.Sfl.) were completed, test-fired and accepted by Wa Prüf in January 1942. A O-Serie of 10 Pz.Sfl.IVb was ordered by Wa Prüf in the Fa11 of1941.
This O-Serie was produced at Krupp-Grusonwerk at the rate of one in August, three in September, four in October, one in November, and one in December 1942.
Troop trials of these self-propelled guns wereto be conducted by a Feld-Versuchs-Batterie assigned to Artillerie-Regiment 16 of the 16.Panzer-Division, which was ordered to be combat ready by 20 September 1942.
On 13 December 1941, Krupp-Grusonwerk was awarded a contract to produce 200 Pz.Sfl.IVb3.
This Pz.Sfl.IVb3 designed for mass production was to have a 320 horsepower Maybach HL 90 P20 185 hp engine and other improvements, including 360 degree traverse. Due to production capacity limitations at Grusonwerk, the assembly contract was transferred to Stahlindustrie in Muelheim-Ruhr by July 1942.
After it was proven that the le.F.H.18 could be successfully mounted on a modified Pz.Kpfw.11 chassis, on 25 July 1942 Hitler directed that the 200 planned Pz.III/IV chassis be quickly issued to mount 200 15 cm S.F.H. This did not work out and the Pz.Sfl.IVb3 production series, scheduled to start delivery in January 1943, was abruptly canceled in early November 1942.
The lenght was 5.9 (with the gun included) the maximum armored protection around 25mm at the front, weight 18,500 kg.
The six roadwheels per side were paired in 3 bogies with internal leaf springs. No torsion bars like the 6 roadwheels panzer IIIs.source
In September of 1939, Krupp designed first real self-propelled artillery piece. Two test vehicles were ordered and completed for tests (V1 and V2). They were tested and then accepted by the army in January of 1942. In 1941, Krupp-Gruson based in Magdeburg, build prototype vehicles armed with 105mm leFH 18/1 L/28 (light field howitzer) gun based on modified Panzerkampfwagen IV's chassis (Sd.Kfz.161). Modified chassis consisted of three-station bogies per side and larger road wheels. Prototypes were fitted with smaller 6-cylinder Maybach HL66P engine with total power of 188 horsepower. Production models were to be fitted with 12-cylinder Maybach HL90 P20k engine with total power of 320 horsepower. Its open-top turret was not fully traversible and could only traverse 70 degrees to the each side. The crew of 4 (commander, 2 gunners and driver) was protected by armor ranging from 14.5mm to 30mm in thickness.
Only 10 prototypes (0-Serie - chassis number 150631-150640) were completed by Krupp-Gruson from August to December of 1942 and were troop tested in Russia with 16th Panzer Division in 1942/43. 200 were ordered from Krupp in December of 1941, but in July of 1942, it became evident that 105mm LeFH 18 can be mounted on modified Panzerkampfwagen II chassis - Wespe. It was then decided to utilize the chassis to mount heavier 150mm sFH but it proved impossible. As a result production scheduled for January of 1943 was cancelled in November of 1942. Sd.Kfz.165's design never reached the production stage as entire self-propelled artillery program was redesigned. Its place was taken by Wespe and StuH 42. Designers planned to use its chassis as a base for Panzerjager armed with 75mm Pak 39 L/48 gun but Jagdpanzer IV was the first to enter production.