Ursus C-45: the Lanz Bulldog built in Warsaw

The Ursus C-45 was the first series tractor of post-war Poland. With production urgently needed, the Ursus works copied the German Lanz Bulldog D9506, which lay in abundance in the former German territories, and built it from September 1947 as the C-45. Its single horizontal cylinder of 10,300 cc produced 45 hp and could be started only with a blowtorch.

Ursus C-45 at a glance

The Polish and English Wikipedia articles agree on the main facts; the detailed technical data comes from the Polish page.

History of the Ursus C-45

At the beginning of 1946 the decision was taken to start producing farm tractors in Poland. Quick action was essential, so the Ursus company copied the German Lanz Bulldog D9506, many examples of which had been left behind after the war; production data and plans formed part of the German war indemnity. Technical documentation was prepared under the guidance of Edward Habich and completed in July 1946. A prototype designated LB-45 was built in early 1947 and publicly shown at the Labour Day parade in Warsaw on 1 May 1947.

Serial production under the C-45 name began in September 1947. By the end of that year 130 tractors had been built, 227 followed in the first quarter of 1948 and 103 in April 1948. In the early 1950s several thousand were made each year. The first tractor, serial number 00001, went to a state farm at Pyrzyce in July 1947, worked on heavy clay soils and ran for 12,000 hours without a major overhaul.

The engine was a single-cylinder two-stroke semi-diesel of 10,300 cc with the cylinder mounted horizontally. It produced 33 kW, or 45 hp, at 650 rpm and ran on heavy oil such as gas oil, with a compression ratio of only 4.75. Starting was an operation in itself: the glow plug at the front was heated with a plumber’s blowtorch, then the steering wheel and column were removed and inserted into one of the flywheels, and the engine was turned over by hand. It demanded strength and practice.

Early tractors ran on steel wheels; rubber tyres came later. On steel wheels the three-speed gearbox gave speeds from 3.5 to 6.2 km/h and a pulling force of 17 kN, while the rubber-tyred version with a road overdrive had six forward and two reverse speeds and reached 16.7 km/h, with a pulling force of 21.5 kN. Fully equipped, the tractor weighed about 3,630 kg on steel wheels and 3,660 kg on rubber.

The C-45 was exported to Brazil, China and Korea; in all about 6,000 C-45 and C-451 tractors went abroad. Its simple, robust and fuel-tolerant engine suited the conditions of the time, although it was heavy, noisy and awkward to handle. Modernisation of the ageing design led in 1954 to the C-451, which replaced it in the Ursus range.

Design and features

• Lanz Bulldog licence-free copy: German plans supplied as part of the war indemnity.
• 10,300 cc single-cylinder engine: 45 hp at only 650 rpm, running on heavy oil.
• Blowtorch starting: the glow plug was heated by hand and the engine turned with the steering wheel.
• Steel or rubber wheels: speeds from 3.5–6.2 km/h on steel and up to 16.7 km/h on rubber.
• Tough and repairable: serial number 00001 worked 12,000 hours before a major overhaul.

Ursus C-45 versions

• LB-45 prototype (1947): the single example shown at the May Day parade.
• C-45 on steel wheels: the early production form, 3 forward and 1 reverse speed.
• C-45 on rubber tyres: with an overdrive giving 6 forward and 2 reverse speeds.
• C-451 (from 1954): the modernised successor with petrol starting and hydraulic lift.

The C-45 was modernised into the Ursus C-451, and the later light tractors began with the Ursus C-328. More tractors are in the Ursus collection.

Video: Ursus C-45 at the harvest

Video by soltys6666 on YouTube.

Sources

• Ursus C-45, English Wikipedia: origin, production, starting procedure, exports
• Ursus C-45, Polish Wikipedia: production figures, technical data, speeds, weights