Sentrarand

[Mudkip Orange]

This is a massive classification yard in the Pretoria/Johannesburg area. It is relatively unique in that it is surrounded by a continuous orbital railway that is nearly 20 km long. Multiple radial rail connections interchange with it in a complex system of flying junctions.

 

https://www.google.com/maps/@-26.06,28.45,13z

 

There are no videos on Youtube. There are three images on railpictures. I'm quite curious how it works operations-wise.

[kvp]

 

I'm quite curious how it works operations-wise.

This doesn't seem to be rocket science. The circular tracks connect with all rail lines, similarly to a roundabout. (see: Paris and Budapest circular railways) They have one connection to the classification yard, that has an incoming area with a hill and a classification area with a small passenger platform on the side. The station is a terminus, so trains reverse to get out by going under the hill (passenger trains have to enter there too). There is a smaller wye at the far end, which allows the turning of locomotives (or even a full set of them). They had so much space that they could afford to waste quite a lot of it.

 

An alternative of this would have been to join the 3 lines with a single wye and branch off the yard with another one frome one of the lines. Another, space saving alternative would have been to create a 4 way junction, where the 3 lines and the yard connect in a crossed diamond pattern. The latter is used at Budapest Nyugati, where the western leg is the Esztergom line (and goes across the Danube river), the northen leg is the Vac line (the oldest railway line in Hungary, with the Rakosrendezo /lit. crab creek classification yard/ immediately north), the southern leg goes into the Nyugati passenger terminal and the eastern leg goes onto the embankment of the circular railway which connects to every other station and line. Trains can go from every direction to every other direction, with a multilevel flying junction. The old Nyugati roundhouse (now a museum) and the Istvantelek shops (used as a museum stock / commuter emu repair shop) are immediately next to the junction. All this in the middle of 3 residential neighbourhoods and the Varosliget park filled with museums +zoo, circus and an old thermal bath.

[Nick_Burman]

According to some South African sources, Sentrarand is a fiasco and part of the reason of the decline in the wagonload network in the Gauteng (Witwatersrand) area. So much so that only one-forth of the project was built.

 

 

Cheers NB

Edited September 29, 2015 by Nick_Burman

[cteno4]

Wow, it is huge, especially if only 1/4 the project.

 

Nick any more info on what went awry?

 

Jeff

Edited September 29, 2015 by cteno4

[Mudkip Orange]

trains reverse to get out by going under the hill (passenger trains have to enter there too).

 

Makes sense. I was thinking the hump was at the southeast by the large multistory operations building, but it's at the northwest, with outbound yards flanking the tracks downstream from the hump. The orbital railway operates clockwise only.

 

This site claims that 40% of the cost of the yard went into a computer system using 1970's tech to automate operation. Intriguingly, despite almost the entire yard being electrified at the ZA 3kV standard, the hump is unwired; they're burning diesel to push all those cars up the hill.

 

A couple things I find interesting about ZA railways: (i) The loading gauge is nearly identical to the Japanese 1067mm network; you could quite literally refit a Japanese EMU for the South African market (or vice versa) simply by adding an electrical transformer. And (ii) The vast majority of the country's freight and passenger rail is hauled with a variant of just two train types. The 5M2A makes up the bulk of every city's commuter fleet, while almost all of the mainline freight is hauled with a variant of the 5E/6E design which was produced from 1954 to 1985. Further stock is based on these platforms; the 10M is a rebuilt 5M2A, while the Class 17E and 18E are rebuilt Class 6E's.

 

A single manufacturer could release a full line of South African N with very little tooling required.

[Nick_Burman]

Wow, it is huge, especially if only 1/4 the project.

 

Nick any more info on what went awry?

 

Jeff

 

Jeff, alas, no. However a well-kown South African railway enthusiast (and former SAR employee) mentions that it was an "umitigated fiasco from the point of view of the customer" and calls it a "white elephant". From what I understand, the yard was created to allow the closure of several smaller facilities across the Rand, however this backfired because it increased the transit times as now cars had to be collected from customers and taken to Sentrarand for classification before setting off on their journeys - and Sentrarand is a loooong way off from either Jo'burg, Pretoria or other important industrial areas in the region. This increased transit times to such an extent that several rail customers gave up and switched over to trucks.

 

 

Cheers NB

[Nick_Burman]

Makes sense. I was thinking the hump was at the southeast by the large multistory operations building, but it's at the northwest, with outbound yards flanking the tracks downstream from the hump. The orbital railway operates clockwise only.

 

This site claims that 40% of the cost of the yard went into a computer system using 1970's tech to automate operation. Intriguingly, despite almost the entire yard being electrified at the ZA 3kV standard, the hump is unwired; they're burning diesel to push all those cars up the hill.

 

A couple things I find interesting about ZA railways: (i) The loading gauge is nearly identical to the Japanese 1067mm network; you could quite literally refit a Japanese EMU for the South African market (or vice versa) simply by adding an electrical transformer. And (ii) The vast majority of the country's freight and passenger rail is hauled with a variant of just two train types. The 5M2A makes up the bulk of every city's commuter fleet, while almost all of the mainline freight is hauled with a variant of the 5E/6E design which was produced from 1954 to 1985. Further stock is based on these platforms; the 10M is a rebuilt 5M2A, while the Class 17E and 18E are rebuilt Class 6E's.

 

A single manufacturer could release a full line of South African N with very little tooling required.

 

 

Minor electrical slipup there - you can't run DC through a transformer. Any Japanese train sold to ZA would require complete rewiring. Better ask UCW to build new ones...

 

AFAIK Sentrarand sees no passenger trains on its tracks.

 

 

Cheers NB

[cteno4]

Yeah the only issues that came up in a quick search was the derelict computer system that apparently was never actually was used and still inactive.

 

Jeff

[kvp]

 

Minor electrical slipup there - you can't run DC through a transformer. Any Japanese train sold to ZA would require complete rewiring. Better ask UCW to build new ones...

Not really, you can just add a high voltage buck converter to each pantograph, that drops 3KV to 1-1.5KV for the japanese sets and disable regenerative braking.

 

 

and Sentrarand is a loooong way off from either Jo'burg, Pretoria or other important industrial areas in the region. This increased transit times to such an extent that several rail customers gave up and switched over to trucks.

Yes and you don't really need classification yards in the age of unit trains and container shipping. Today for most of the world freight is moved in either fixed bulk or container trains or switched in groups, like direct coaches. The latter needs lots of small switching yards with a single shunter to cut and join smaller fixed groups of cars from directional trains. These arrangement give the highest service level for customers.