Classification and Layout of Marshalling Yards
Classification of Yards
- Terminal yard - Terminal yard means yard attached to terminal goods shed where large number of wagons are loaded, unloaded. This term is also used for every goods yard, where a goods train terminate.
- Marshalling yard - Yards are nominated as Marshalling yards on the basis of number of wagons dealt with. The concept of Marshalling yard are becoming anachronistic and world over it is giving way to freight terminals.
- Transit yard - Trains are received and despatched without any shunting on them. In such yard generally change of crew, engine, C&W examination, etc. are carried out.
Types of Marshalling Yards
- Sorting by push and pull method of shunting.
- Maximum number of wagons that could be sorted out in a flat yard with one shunting neck and one shunting engine will be around 500 or so in aday.
- If the total quantum of traffic is more than this it is advisable to have a hump yard or separate Up and Down Yards.
- Flat yards are economical in space, but slow in working and wasteful in shunting engine hours.
- A hump of suitable height is provided and wagons are rolled from the crest of hump to desire sorting lines with gravitational force.
- With proper mechanisation it is possible to sort upto 5000 wagons per day in a single hump.
- One train load of 60 wagons can be sorted in 20-25 minutes in no-mechanised hump yard.
- With retarders it can be done in 12-15 minutes.
- In fully mechanised yards it can be done in 7-8 minutes.
- Hump yard are economical in Shunting Engine Hours compare to Flat yards.
- Natural slope of the site is taken to locate reception and sorting lines in such a fashion that wagons can be rolled from reception to sorting lines without the help of a shunting engine.
- Wagons on reception lines are held in position by track brakes.
- Main advantage is the reduction in operating costs due to saving in shunting engine hours.
- Economical than Flat yard, but layout is dependent on the availability of plenty of land with the required topography.
Layout of Marshalling Yard
Keeping in view of the following
- Pattern of Traffic
- Topography & availability of land.
- Economy, both in capital and recurring costs.
- Flexibility, ensuring maximum simultaneous movements without sacrificing safety.
- Room for further expansion
Fewer, bigger yards
World over Railways are shifting towards the concept of Fewer, bigger yards. This has the following advantages :
- Less multiple handling and as such less delay to wagons and less damage to wagons/consignments.
- Possibility of getting greater number of long distance bulk loads .
- Less idling of assets and staff during slack season.
- Sub yards.
- Reception yards
- Hump and sorting yards
- Departure yard
- Grid yard(For sorting of local wagons and forming section and transhipment trains in geographical order).
- Through yard/Bypass yard
- Sick lines
- Transhipment yard or repacking yard
- Exchange yard
- Lighting, staff amenities
Telecom Equipment in Marshalling Yard
- Telecom Network – Extensive telecom network through an electronic exchange and intercoms between all important points of Yard is essential. Yards should have direct dialling and Trunk facilities and Control phones.
- Paging and Talk-back arrangement – through which orders and instructions are issued from a central point. Similarly staff can convey any information to the Central point. This facilitates better co-ordination.
- Loud speakers at convenient positions for conveying instructions to different staff in same area. For eg. Loud speakers are provided in sorting yard so that in charge of hump can convey instructions relating to hump cabin and skid porters.
- Extensive use of walkie-talkies