Grass catcher (tram)
The catcher is a safety device in older high-floor - tram railcars designed to prevent the crossing of animals or objects. An alternative name is basket protection device .
development
The electrification of many trams at the end of the 19th century made it possible to travel at speeds that pedestrians in city traffic were previously unfamiliar with. The tram operators tried to counter the increased risk of a personal accident through various protective measures. In addition to rail clearers and so-called protective vests - made of steel band, arched grids on the front of the vehicle - which were supposed to "smack back" the inattentive passers-by, fixed collecting baskets were initially used. These should catch a person lying in front of the vehicle in an emergency so that they were not run over. The uneven paving of the streets and the short wheelbase of the usually two-axle vehicles, which tended to nod as a result, meant that the vehicles equipped with them frequently hit the ground.
In their edition of October 1, 1896, the Technische Mittheilungen and Advertisements presented the invention of a Mr. Ramm from Hamburg. The movable collecting basket developed by him was normally locked in such a way that a sufficient distance from the upper edge of the rail was guaranteed. In front of it was a tactile grid, also known as a tactile bar. As soon as a larger object hit the tactile grille, the grass catcher automatically fell to the ground under its own weight and forks the object it hit. Ideally, people are only dragged along and slightly injured, but not rolled over - at least this is the case in the lower speed range. The tactile grids and collecting baskets were initially made of wood, later versions were made of steel grids to prevent injury from wood splinters.
The inspection of the safety gears was one of the measures that the tram drivers had to take before leaving the depot. Depending on the company, there could be reasons why the device had to be locked. In Rostock , for example, the collecting basket had to be hung in before climbing switches and support rails were used and then released again after leaving. In Berlin, it was planned to hang the elevator in the event of a defective elevator or when the snow cover was so high that the elevator lever had to be held in place continuously to prevent permanent release. At the transition from tram cars to the railway network, such as the Berlin line 120 or the Vienna line 18G , the baskets also had to be determined. Defective safety devices were one reason for the abandonment of a railcar.
The tram construction and operating regulations (BOStrab) of November 13, 1937 provided for the equipping of trams with track clearers or safety guards under Section 17. The version of the BOStrab, which has been valid since 1987, no longer expressly prescribes safety devices such as collecting baskets, but according to § 41 (3) allows other devices to take over the tasks of track clearers or track clearers to protect against derailment caused by obstacles.
Individual evidence
- ↑ Bernhard Kauntz: The “Electric” - The Development of the Tram in Vienna. In: www.werbeka.com. July 2, 2008, accessed March 27, 2017 .
- ^ Alfred Horn: Wiener Stadtbahn. 90 years of light rail, 10 years of underground. Bohmann-Verlag, Vienna 1988, ISBN 3-7002-0678-X , pp. 142-143.
- ↑ a b c d Lutz Habrecht: A chapter on security. Protective devices on trams . In: Verkehrsgeschichtliche Blätter . Volume 2, 1991, p. 36-39 .
- ↑ Hans-Jürgen Kämpf: The tram in Spandau and around Spandau . Ed .: Heimatkundliche Vereinigung Spandau 1954 e. V. Berlin 2008, ISBN 978-3-938648-01-8 , pp. 185-199 .
- ↑ Ordinance on the construction and operation of trams. Section 41 Railway clearers and rail clearers . ( gesetze-im-internet.de [accessed April 1, 2017]).