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South Africa diesel locomotives controversy


bikkuri bahn

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bikkuri bahn

Pretoria - The Passenger Rail Agency of SA (Prasa) says the locomotives it acquired are the best in the world, and they are suited for local tracks.

Group CEO Lucky Montana briefed reporters in Pretoria on Monday following a report in Rapport newspaper at the weekend that South African railway officials imported brand new locomotives from Europe worth hundreds of millions on rands, despite explicit warnings that the trains were not suited for local rail lines.

 

more:

http://www.news24.com/SouthAfrica/News/Our-locomotives-are-best-in-the-world-Prasa-20150706

Edited by bikkuri bahn
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Sounds like a big cock fight.  Agency boss, rail boss and news boss all fighting it out.  Whom will have the biggest manhood by the end?

Edited by katoftw
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From:  https://en.wikipedia.org/wiki/South_African_Class_Afro_4000

 

The South African loading gauge specification submitted during the tender phase was, however, one that made special allowance for the pantographs on electric locomotives to exceed the actual maximum height of 3,965 mm (13 ft 0.1 in). The correct South African loading gauge specification for diesel-electric locomotives and other rail vehicles, specifying a maximum height of 3,965 mm (13 ft 0.1 in) above the railhead, was submitted to the manufacturer in October 2013, after the locomotive design was completed. Since reducing the locomotive height to 3,965 mm (13 ft 0.1 in) would require a complete re-design of the vehicle equipment and the carbody structure, and since the Afro 4000 locomotive, as already designed, would fit into the first submitted loading gauge for electric locomotives, PRASA accepted the locomotive design at the 4,140 mm (13 ft 6.99 in) height.[19]

 

In January and February 2014 PRASA conducted height verification at bridges with notable height constraints at Jeppe, Denver, Driehoek and New Era, towing Class 7E2 no. E7201 which is 4,190 mm (13 ft 8.96 in) high with pantographs down and with a carbody height of 3,942 mm (12 ft 11.2 in). Of these locations, the lowest measured height of the contact wire above the railhead was 4,150 mm (13 ft 7.39 in) at Denver. The pantographs in the housed position began to foul and lift the contact wire approximately 10 m (33 ft) from the bridges, and at Denver and New Era stretched the cross spans.[20]

 

Similar tests were carried out between Beaufort West and Cape Town, towing Class 7E no. E7058 which is 4,200 mm (13 ft 9.35 in) high with pantographs down and with a carbody height of 3,942 mm (12 ft 11.2 in).

 

The resulting report concluded that the Afro 4000's structure gauge does not fit in the South African infrastructure clearance envelope. While the PRASA rolling stock, the Class 7E and 7E2 locomotives that were used during the tests, also do not comply with the structure gauge clearance under the bridge, there is no direct contact of the carbody with the overhead contact wire due to the fact that the pantographs are insulated from the roof. The Afro 4000, however, has a minimum calculated roof clearance of only 10 mm (0.39 in), which poses an operational electrical risk. Since it does not fit the designed earth clearances at bridges and tunnels and the height of the locomotive encroaches too close to the contact wire, the risk to the driver and the locomotive is high. One of the recommendations was that delivery of the Afro 4000 should be delayed pending a suggested design review.[20]

 

In spite of the recommendations, the first locomotive was delivered in November 2014. In July 2015, with thirteen locomotives already delivered and after a press report about the excessive height of the Afro 4000 locomotive, PRASA denied that the locomotive's height was excessive and insisted that it had followed a strict design review process.[21

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Davo Dentetsu

Oh my flipping god, these are basics in railway running 101!  Does the stuff fit anything?  If it chuffing doesn't, you have problems!

AnsaldoBreda must be glad someone else looks like a fool for a change.

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This is why there is an international freight interchange standard. British loading gauge is the narrowest and the italian is the shortest around the old prussian freight interchange minimum. The old hungarian dsa mallets would be too large for the current international standard and the us army transportation corp locomotives donated to hungary got a cab and chimney extension since they were designed to run both in the narrow british and short italian loading gauge.

 

One possible solution would be to switch from ballasted to ballastless track on the problem section to lower the rail height.

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The tunnel are in Italy but they are after Ventimiglia toward France, so they are of SNCF, not of RFI, so the is French problem. Those trains already had problems on France's network. They had problems with some platform of the network Francese.

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bikkuri bahn

Next time, they should knock together a plywood cutout of the profile of the proposed rolling stock, mount it on a flatcar and run it on all the lines- any "bumps" and it's either back to the drawing board or "don't run it" on that line.  Or just ask the engineering dept. of the railway(s) to open their records...

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The problem is usually that the manufacturer has paid lots of money to the politicians to purchase their products, which means they have to win and whatever they ship must be accepted and put to some use. The second reason is usually utter incompetence, where the management at each company fail to understand anything.

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Boy, I know what this one's like. I've had the misfortune of working on a piece of third rail powered equipment that was unfortunately designed to the wrong third rail specification. The manufacturer did their part in that they designed it to the spec they were given it's just that the vehicle won't survive long on the third rail if used in service. It's been parked now for several years.

 

Here's what I get out the timeline of the PRASA project from the wiki page: contract signed in October 2013 for a stock design with first delivery within about one year (this, by the way, is a short lead time), also in October 2013 PRASA gives Vossloh documentation that shows the maximum height on diesels should be roughly 6 inches lower than what they originally had in the spec. Vossloh says design is already done at this point so too bad. PRASA could have told Vossloh that this change has to be made at this point but this would have required a contract modification with big delays and lots of money involved. They decided to duck the issue as PRASA clearly wanted to get these units in service as quickly as possible (one would guess that there were political considerations behind this). The units show up and are found to get too close to the wire because the railroad doesn't seem to know their own clearances: an electric built in the 1980's couldn't make it under a bridge with the pans down. From my experience this is not as uncommon as one would think especially on older systems. Rather than designing to the physical limits of the infrastructure, I know of several operators who design to the weights and clearances of their older stock on the assumption that if it worked before it will do so again. The only problem is that unless you go out and measure, you don't really know if it did work before. If nothing else, they can cut the wheels down and run them with thin tires. They'll have to hope that these things don't also have a problem with wheel wear.

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Nothing new there.  Our new EMUs from India won't be able to pass on certain curves or they will side swipe one another or pass through some curved platforms because they are longer than our existing trains.  What happens when the railway is not allowed to have a say in ordering new rolling stock.

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There are multiple options:

-lowering the rail height by using ballastless tracks

-lowering the rail height by excavating under the bridges and carving the bottom of any tunnels

-raising the contact wire by stringing it up more tightly or switching to ceiling mounted contact rails

 

If everything else fails, you have to rebuild. For example the horseshoe shaped tram tunnel around the anchor chamber of the Chainbridge in Budapest was designed for 8 meter 2 axle trams. It was still possible to squeeze through 12 meter bogie cars with their narrowing ends, but later articulated ones could only fit through by moving the tracks closer to the middle and using a single tram only rule. Modern low floor ones would get stuck and couldn't handle the 12% percent gradient with little to no transition. This tunnel had to be demolished and is being rebuilt for the new low floor articulated units. The ramps will be more gentle and the curves broader. There are times when you couldn't keep the oldest standards forever.

 

Except when you want to keep something in the original state, like the old Budapest underground like, which still has most of its original 1896 stations and tunnels, so it still keeps its special loading gauge that had to be used to fit between the surface and the sewer system as back in the 19th century nobody dared to route an electric train under water pipes and the now fully covered old shipping canal under the grand boulvards. The only changes were the replacement of wooden ties with concrete ones (for fire safety) and turning it from left hand to right hand running. Regardless, the original 19th century cars can still run on the line and they occasionally show that. (the overhead contact rails are so close that if you pull down the pantos under power, they just arc throuh, clearence is around 3 inches between roof and overhead rail) But getting new rolling stock for a 19th century underground is next to impossible as everything has to be custom built.

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