Otto Martin Maschinenbau S 11
Built: 1949–1950 · Series: S
More machines from model year 1949
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Otto Martin Maschinenbau S 11 (1949-1950): single-cylinder diesel tractor with evaporative cooling, 8.1 kW output and a top speed of 15 km/h from the S series
The S 11 was built in the first post-war years of 1949 and 1950 as a small farm tractor of the S series and, like many models from these early post-war years, belongs to the group of simple single-cylinder diesels aimed at smaller agricultural holdings.
Read on 3 more paragraphs
The single-cylinder diesel engine displaces 1,099 cm³ and delivers 8.1 kW, equivalent to 11 horsepower. Cooling is evaporative, relying on the boiling-off of water rather than a pressurised circuit with a pump. With a weight of 1,270 kg, a wheelbase of 1,630 mm and a top speed of 15 km/h, the S 11 was a typical small tractor for fieldwork on smaller plots.
Evaporative cooling was a common solution for small German diesel tractors in the 1940s and early 1950s, doing without a radiator, pump and thermostat: the coolant heats up during operation and partly boils off, so it must be topped up regularly. This design lowered production costs but required close monitoring of the water level.
When buying a used S 11, the condition of the evaporative cooling system is decisive: if the original coolant tank is missing or leaking, the engine overheats quickly. The single-cylinder injection pump should also be checked, since spare parts for this little-known maker are only available to a limited extent. Anyone restoring one should expect to have worn parts remade individually rather than ordered from stock.
Sources: SpecCodex-Register: Kennwerte des Modells S 11
Technical data
Engine
| Fuel | dieselcorrect |
|---|---|
| Power | 11 hp (8.1 kW)correct |
| Rated speed | 1.100 (1.500?) rpmcorrect |
| Cylinders | 1correct |
| Displacement | 1,099 cm³correct |
| Cooling | water-cooledcorrect |
Dimensions and weights
| Length | 2,550 mmcorrect |
|---|---|
| Width | 1,555 mmcorrect |
| Height | 1,450 mmcorrect |
| Wheelbase | 1,630 mmcorrect |
| Ground clearance | 240 mmcorrect |
| Unladen weight | 1,270 kgcorrect |
Drivetrain and chassis
| Drive | rear-wheel drivecorrect |
|---|---|
| Gearbox | 4V+1Rcorrect |
| Front tyres | 5.00-16correct |
| Rear tyres | 8.00-20 ALcorrect |
| Top speed | 15 km/hcorrect |
Origin and approval
| Construction | frame constructioncorrect |
|---|---|
| Units built | 67correct |
Where this model stands
Power-to-weight ratio: 6.4 kW/t (8 kW / 1.3 t)
Power class: Compact (< 40 hp)
Stronger than 1% of the tractors in the register — out of 15,663 models with a stated power figure.
Calculated from the documented figures above — not a rating.
Frequently asked questions
How much power does the Otto Martin Maschinenbau S 11 have?
The Otto Martin Maschinenbau S 11 delivers 11 hp.
How much does the Otto Martin Maschinenbau S 11 weigh?
The unladen weight is 1,270 kg.
What engine does the Otto Martin Maschinenbau S 11 have?
1 cylinders, 1,099 cm³ displacement, Diesel.
How fast does the Otto Martin Maschinenbau S 11 go?
Top speed is 15 km/h.
What are the dimensions of the Otto Martin Maschinenbau S 11?
2,550 mm × 1,555 mm × 1,450 mm.
When was the Otto Martin Maschinenbau S 11 built?
Production years: 1949–1950.
What to check before buying
- Check the hour meter against the service records — a replaced instrument is the most common gap.
- Compare the data plate and chassis number with the papers.
- Check the weights in the papers against the figures here — attachments change them.
- Check front and rear tyre sizes: mismatched pairs strain the drivetrain.
- Shift the gearbox cold and warm — jumps only show up at temperature.
- Load the hydraulics and watch for sag.
- Ask about parts availability for this build year — the running costs hang on it.
A general list for this type of machine — no substitute for an inspection or an appraiser.
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This page carries 20 individual figures for this model. They come from 1 recorded source; every figure can be traced there. What we cannot document is not here — we leave gaps open rather than estimate them.
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Sources: Wikibooks Traktorenlexikon (CC BY-SA 4.0) (retrieved August 2026) · Values adopted and presented in our own form; changes from the source are possible. · How we check the data
Tractor in 3D section
Turn the model, look inside and click an assembly — each one is explained.
