Holy Cow Tractor Pulling Team

Ballast tamper

A ballast tamper or tamping machine is a machine used to pack (or tamp) the track ballast under railway tracks to make the tracks more durable. Prior to the introduction of mechanical tampers, this task was done by manual labour with the help of beaters. As well as being faster, more accurate, more efficient and less labour-intensive, tamping machines are essential for the use of concrete sleepers since they are too heavy (usually over 250 kg (551 lb)) to be packed into the ballast by hand. Early machines only lifted the track and packed the ballast. More modern machines, sometimes known as a tamper-liner or tamping and lining machine, also correct the alignment of the rails to make them parallel and level, in order to achieve a more comfortable ride for passengers and freight and to reduce the mechanical strain applied to the rails by passing trains. The majority of track machines are powered by a diesel engine. This provides power to the driving wheels via a cardan shaft, allowing the machine to propel itself to and around a work-site. The engine also drives an hydraulic pump to provide power for the various tools. [edit]Tamping units A closeup of a Plasser & Theurer 08-4x4/4S-RT Unimat 08-RT Tamper at Bristol Temple Meads Unimat 09-32/4S at work For each rail there is a tamping unit attached to the main frame by means of vertical guide columns and a lifting / lowering hydraulic cylinder. The tamping unit consists of tamping tools (arms or "tines"), a vibration motor (hydraulic motor), a vibration shaft and an eccentric flywheel. For each sleeper, a tamping unit is provided with four pairs of tamping arms: one each side of the sleeper, i.e., 16 tamping arms are used for tamping a single sleeper.[vague] To process several sleepers simultaneously, a tamping unit may have 32 arms (for two sleepers), leading to the derivation of machine type numbers: "16" indicates 16 tines, enough for single sleeper, "32" for two sleepers, etc. Tamping units of a Unimat have swivelling tamping arms to pack points and crossings. Special units are available for use with third-rail electrified track. [edit]Universal tamping machine This type of straight-track tamping machine is the oldest of the varieties. It uses a two-chord lining system for alignment of track (for slewing the track to left or right, as-and-when required). This type of lining is controlled mechanically. The machine has four bogies, one at the front, one at the rear, a third in the centre and a fourth in between the centre and the rear. They are called: front-tightening, rear-tightening, lining bogie and measuring bogie, respectively. The measuring bogie determines the amount of slewing required and measures the subsequent adjustments applied by the lining bogie. The lining bogie also lifts the track to make it level. The tamping bank behind the lining bogie has a vibrating motor and four arms for each rail.

C.O.W. Systems