The Ursus C-355 was the middle tractor of the early 1970s, produced in Warsaw from 1971 to 1975 as a developed version of the C-4011 and the direct forerunner of the C-360. A 45 hp four-cylinder diesel, a 10/2 gearbox and a 1,200 kg lift made it the standard machine on Polish state farms of the period.
Ursus C-355 at a glance
| Maker | Zaklady Mechaniczne Ursus, Warsaw, Poland |
|---|---|
| Production | 1971–1975 |
| Developed from | Ursus C-4011 |
| Successor | Ursus C-360 |
| Industry class | 0.9 t |
| Engine | Ursus S-4002, four-cylinder diesel |
| Displacement | 3,121 cc |
| Power | 33 kW (45 hp) at 2000 rpm |
| Torque | 175 Nm at 1500 rpm |
| Gearbox | 10 forward / 2 reverse, with reducer |
| Speed range | 1.13–25.6 km/h |
| Lift capacity | 1,200 kg |
| PTO | 540 rpm, dependent and independent |
This page is based on one source, the Polish Wikipedia article on the Ursus C-355.
History of the Ursus C-355
The C-355 was the first stage of modernising the C-4011. Design work at the farm tractor research centre was carried out between 1966 and 1968, and the stage was completed in the fourth quarter of 1969 with 50 tractors of an information series designated C-345. Serial production under the C-355 name began on 1 April 1971, and from 1975 the developed C-355M was built, leading directly to the C-360.
The changes from the C-4011 were extensive. The bonnet looked different, the engine was tuned to 45 hp and the steering changed to a screw-and-ball mechanism. The twin-rod steering was replaced by a single-rod system, the under-bonnet hook gave way to a trailer hitch, and the double oil filter was replaced by a centrifugal filter. A new dashboard carried two round gauges, an hour meter and a control gauge.
The final drive ratio was changed from 55/12 to 56/11 teeth, trading top speed for pulling power, and the steering box became a bolt-on unit instead of being cast into the gearbox cover. The brake distributor was replaced by two pedals joined by a latch, the handbrake moved to the final drive housing, the injection angle changed from 20 to 22 degrees, and the single PTO shaft became a double split shaft. A second hydraulic coupler was added.
The C-355 also proved itself on long journeys. In 1971 a student expedition covered about 10,000 km through the Soviet Union, Romania, Bulgaria, Turkey, Syria and Lebanon with a Jelcz PO-1 trailer, and the same tractor, after repairs, set off again the next year. In 1972 a C-355 covered 14,000 km from Warsaw to Kuwait and back in 80 days.
The engine was the S-4002, a four-cylinder diesel of 3,121 cc producing 33 kW at 2,000 rpm and 175 Nm at 1,500 rpm, with a PZL-Mielec injection pump and a specific consumption of 270 g/kWh. The unsynchronised gearbox with a reducer gave ten forward and two reverse speeds and a range from 1.13 to 25.6 km/h. The hydraulic lift delivered 20 litres a minute at 12 MPa and raised 1,200 kg, and the first tractors came with a wooden crate of spare parts.
Design and features
- 45 hp S-4002 diesel: 3,121 cc, 175 Nm, a solid step up from the C-4011.
- 10/2 gearbox: an unsynchronised box with reducer and a wide speed range.
- Screw-and-ball steering: lighter and more precise than the old twin-rod system.
- Split PTO shaft: dependent and independent drive at 540 rpm.
- Proven on long expeditions: C-355s covered 10,000 and 14,000 km journeys in 1971 and 1972.
Ursus C-355 versions
- C-345 (1969): 50-tractor information series that preceded serial production.
- C-355 (1971–1975): the standard production model.
- C-355M (from 1975): developed version and the first step towards the C-360.
- Early and late C-355s: the first examples had one hydraulic coupler and some C-4011 instruments.
The C-355 was replaced by the Ursus C-360 and followed the earlier Ursus C-328 in the light and middle range. More tractors are in the Ursus collection.
Video: Ursus C-355 against a Zetor 7011
Video by tractor fight channel on YouTube.
Sources
- Ursus C-355, Polish Wikipedia: history, changes from C-4011, expeditions, technical data
