• Passenger quad B (8-axles) locomotive for narrow (Cape) gauge with speed up to 100 mph (161 km/h)

  • General discussion about locomotives, rolling stock, and equipment
General discussion about locomotives, rolling stock, and equipment

Moderator: John_Perkowski

  by CM20EMP
 
Please pardon my language as I'm not a native English speaker nor have I been extensively educated in English.

Hi, I'm from Indonesia and as most of Indonesian railroad are of lightweight narrow-gauge construction (1067mm / 3' 6" Cape gauge with 18 metric ton axle load), which means that a six-axled locomotive with double 3-axle bogies (in the form of C-C or Co'Co') can only be as heavy as 108 metric tons, including fuel and motor oil. This means that the most powerful locomotive for this segment would've been Stadler's AsiaLight for KiwiRail in New Zealand (3,000 kW, starting tractive effort 415 kN, 100 km/h 63 mph) or TRA in Taiwan (2,015 kW, STE 395 kN, 120 km/h 75 mph) . A more powerful and faster locomotive for passenger service that also need to fit the smaller loading gauge would likely require more axles and wheels for the delivery of more power, such as ES43BBi (axle load 25 metric tons, 3,206 kW, 165,347.7 lbf / 735 KN, 40 mph or 65 km/h ) or F125 (130 metric ton weight, which will require 8 axles for sub-18 ton axle load).

I have been unable to locate whether ES43BBi uses a span bolster or lateral motion device (such as the roller ones), other than some pictures that are paywalled in trainorders dot com. Do you think it's better for 100 mph narrow gauge locomotive to use span bolster vs roller device? Can anyone ascertain whether ES43BBi uses span bolster or not?
  by Pneudyne
 
The Wabtec ES34BBi uses span bolsters, as does the EMD SD70ACe-BB.

The only implementation of a four bogie locomotive with roller platform lateral motion was the Westinghouse gas turbine electric prototype of 1950. One could say that since then, the span bolster type has been the running gear of choice where eight axles, all powered, are required under a single frame.

The GBB span bolster assembly used under the SD70Ace-BB is an integrated design that has the advantage that it does not incur any ride height penalty as compared with conventional bogies. Thus, it would appear to be applicable for Cape/metre gauge applications with restricted loading gauges.

Back in 1969, CEM (France) built a Cape/metre gauge eight-axle span bolster locomotive for service on the French Outre Mer (overseas) railway systems in Africa. It provided up to 4000 cv on 128 tonnes, for a 16 tonne axle loading, and had a fairly compact profile. Thus, in a broad sense, what you envisage has been done before. This locomotive had a brief mention in this thread: https://www.railroad.net/eight-axle-loc ... 62408.html.

By the way, that span bolster running gear can be suitable for high-speed operation was demonstrated by the Union Pacific back in 1936. Five of its Streamliner power cars (locomotives) were of the articulated body type, but instead of a single central bogie under the body articulation joint, they had a span bolster riding on a pair of two-axle bogies.

Coincidentally, there is a current discussion on locomotives with span-bolster running gear on the WDL forum.


Cheers,
  by Pneudyne
 
Another approach to placing eight axles under a single frame is apparent by looking backwards to the GE-built PJKA CC200 class of 1953. This was of the tribo form, with the Co-2-Co wheel arrangement. Using a powered centre bogie, making it Co-Bo-Co, would provide the desired eight powered axles. Note that prior to building the CC200, GE had built a Co+Bo+Co road switcher for service in Guatemala and Colombia. This had low-speed articulated bogie running gear to suit the applications, but it also established the concept of the eight axle tribo type.


Cheers,
  by CM20EMP
 
Pneudyne wrote: Sat May 18, 2024 2:43 am The Wabtec ES34BBi uses span bolsters, as does the EMD SD70ACe-BB.

The only implementation of a four bogie locomotive with roller platform lateral motion was the Westinghouse gas turbine electric prototype of 1950. One could say that since then, the span bolster type has been the running gear of choice where eight axles, all powered, are required under a single frame.

The GBB span bolster assembly used under the SD70Ace-BB is an integrated design that has the advantage that it does not incur any ride height penalty as compared with conventional bogies. Thus, it would appear to be applicable for Cape/metre gauge applications with restricted loading gauges.

Back in 1969, CEM (France) built a Cape/metre gauge eight-axle span bolster locomotive for service on the French Outre Mer (overseas) railway systems in Africa. It provided up to 4000 cv on 128 tonnes, for a 16 tonne axle loading, and had a fairly compact profile. Thus, in a broad sense, what you envisage has been done before. This locomotive had a brief mention in this thread: https://www.railroad.net/eight-axle-loc ... 62408.html.

By the way, that span bolster running gear can be suitable for high-speed operation was demonstrated by the Union Pacific back in 1936. Five of its Streamliner power cars (locomotives) were of the articulated body type, but instead of a single central bogie under the body articulation joint, they had a span bolster riding on a pair of two-axle bogies.
Thank you for the information, including the fact that there was already a high-speed application for the locomotives with span bolster


Coincidentally, there is a current discussion on locomotives with span-bolster running gear on the WDL forum.


Cheers,
What does 'WDL' mean in this case, is it another subforum? I'm new to the railroad.net


Pneudyne wrote: Sat May 18, 2024 2:54 am Another approach to placing eight axles under a single frame is apparent by looking backwards to the GE-built PJKA CC200 class of 1953. This was of the tribo form, with the Co-2-Co wheel arrangement. Using a powered centre bogie, making it Co-Bo-Co, would provide the desired eight powered axles. Note that prior to building the CC200, GE had built a Co+Bo+Co road switcher for service in Guatemala and Colombia. This had low-speed articulated bogie running gear to suit the applications, but it also established the concept of the eight axle tribo type.


Cheers,
Yes, but would this triple-bogie wheel configuration be suitable for passenger service with up to 160 km/h or 100 mph? According to Indonesian WIkipedia CC200 locomotives
were only able to run up to 100km/h or 63 mph, not to mention that a middle bogie will split the space under the underframe / chassis into two ends
  by Pneudyne
 
High-speed would not be a problem for properly designed tribo locomotives. For example, the Channel Tunnel 9000 class Bo-Bo-Bo electric locomotives run up to 160 km/h. There is probably much more recent high-speed experience with tribo types than with span bolster types.

In the diesel case, the fact that the centre bogie of a tribo unit occupies underframe space is certainly a potential disadvantage that would probably be a persuasive negative in many, but perhaps not all cases.

(WDL = World-Diesel-Locomotives forum on Groups.io.)


Cheers,