Caterpillar tractor

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Chain tractor Holt from before 1925
Modern crawler tractor John Deere 9420T

A caterpillar tractor or chain tractor is a motor vehicle that is used in different areas of application, for example in earthworks , agriculture and forestry, in the military, in road construction, construction machinery technology or slope clearance in ski areas. A caterpillar tractor is equipped with caterpillar chains (technically also caterpillar chains ), so that it can be used as a tracked vehicle preferably on poorly stable, loamy ground on which wheeled tractors and other wheeled vehicles sink in and fail. Depending on the use and, if necessary, attachments, crawler tractors can be, for example, tractors or self-propelled machines .

function

Fiat 331C caterpillar in the Auto & Technic Museum Sinsheim

Crawler tractors are used for towing work machines or directly as a sealing machine. Since they have a relatively low specific soil pressure, they have to be weighted down for compaction work. Like the bulldozers , the crawler tractors are not specific compaction machines, but they do have some special tasks. In earthworks, they are the most common construction machines, as they exert static ground pressure when driving over loosely heaped ground; due to their narrow working width per transition, they only achieve the same compaction effect or performance compared to rubber-tyred rollers when they are driven over multiple times . Because their chains wear out quickly, they are only suitable for compacting short embankments, damp earth, mixed types of soil. However, they are unsuitable on loose, stony surfaces.

Compared to a crawler tractor, a wheeled tractor (tractor) can usually drive much faster and has different gear ratios, but fails on construction sites with slippery, wet floors. The crawler tractor makes up for its low driving speed with its function as an efficient tractor and low ground pressure; It is economical to purchase where it is used to transport loads and where speed is not important.

Agricultural crawler tractors have similar drive systems (hydraulics) to military armored vehicles. Most of the other crawler vehicles used in the civil sector were previously equipped with manual transmissions, today the clear trend is towards completely hydraulic drives, primarily based on hydrostatic conversion .

In military terms, crawler tractors are mainly used as artillery tractors to move heavy artillery. In modern armies, however, they are used less and less because off-road trucks and self-propelled guns take over their role.

History and origin of the word

Crawler tractor T-100 in the Technik Museum Pütnitz

The first caterpillar tractor with Otto engine was built by Holt in 1906 , then in 1931 the first caterpillar tractor with a diesel engine.

Joseph Vollmer , who was responsible for the first German armored vehicles , developed a caterpillar tractor for civil use immediately after the end of the First World War . These so-called WD caterpillar tractors from the Deutsche Kraftpflug-Gesellschaft Berlin were manufactured by Hannoversche Maschinenbau AG (Hanomag). Similar vehicles were also built under license by Podeus in Wismar and by Dinos-Werke in Berlin. The tugs were manufactured in two sizes: with 20 HP (later 25 HP, 4 cylinders, bore × stroke: 90 mm × 150 mm) and 50 HP (4 cylinders, 130 mm × 155 mm) engines. The engines were equipped with a Grätzin heavy oil gasifier that ran on petroleum.

The Lemma Raupenschlepper is a loan translation from the English of caterpillar tractor ( caterpillar English for caterpillar ; tractor English for tractor), which has been documented since 1915. The Podeus company constructed chain tractors that were called "caterpillar tractors" for the first time.

Individual evidence

  1. ^ A b Norbert Gebhardt: Fluid technology in motor vehicles . Springer-Verlag, 2010, ISBN 978-3-642-05482-2 , pp. 183 f., 216 ( google.de [accessed on April 16, 2019]).
  2. ↑ a b Georg Garbotz: Handbook of mechanical engineering in construction: third volume The devices for earth and rock movements . Springer-Verlag, 2013, ISBN 978-3-662-32913-9 , pp. 460 ( google.de [accessed on April 16, 2019]).
  3. ↑ W. Striegler, D. Werner: Dam construction in theory and practice . Springer-Verlag, 2013, ISBN 978-3-7091-7972-7 , pp. 371 ( google.de [accessed on April 16, 2019]).
  4. ^ O. Walch: Construction machinery and construction equipment: First volume: Construction machinery . Springer-Verlag, 2013, ISBN 978-3-662-26651-9 , pp. 50 ( google.de [accessed April 17, 2019]).
  5. ↑ Erwin Neumann: The modern road construction: tasks and technology . Springer-Verlag, 2013, ISBN 978-3-662-30748-9 , pp. 21 ( google.de [accessed on April 16, 2019]).
  6. ↑ Günter Kühn: The mechanical earthwork . Springer-Verlag, 2013, ISBN 978-3-663-08094-7 , pp. 72 f . ( google.de [accessed on April 16, 2019]).
  7. ↑ Technical Central Sheet. Mechanical engineering department . 1955 ( google.de [accessed on April 16, 2019]).
  8. ^ A b Walter J. Spielberger: Military Vehicles 02. The Panzerkampfwagen I and II and their variants. Including the tank developments of the Reichswehr. Motorbuch, 1974, ISBN 3-87943-335-6 , p. 10 .
  9. ↑ Ulrike Haß-Zumkehr: German dictionaries - focus of language and cultural history . Walter de Gruyter, 2012, ISBN 978-3-11-084918-9 ( google.de [accessed April 22, 2019]).