# MISC | Effects of axle load and speed on performance and maintenace



## makita09 (Sep 8, 2009)

Also, I should add, wheel maintenance is important. The rounder the wheel the less wear it causes, but if the wheel has suffered flats caused by locking during breaking then small imperfections are created in the wheel geometry, hence why modern maintenance depots now have computer controlled laser guided wheel lathes.

It must also be said that the Japanese are good at dealing with all of the elements involved.


----------



## Suburbanist (Dec 25, 2009)

railzilla said:


> US roads can live with a bad track quality. If a good track is needed Amtrak has to pay for it. Again it shows that freight and passengers shouldn't mix.





railzilla said:


> So it would make sense to ban freight from the most traveled passenger corridors. Track prices are kilometer based but if you price a longer less direct route with a lower track standard is cheaper, the cargo companies will use it. It doesn't matter if a train with bulk takes a few minutes longer. Fast freight would have to use EMU or DMU just like passengers. See the M250 super cargo express form JR freight.


Indeed, instead of banning freight they should cut off passenger service in inferior railways (V<140 km/h) and segregate passenger and freight. Then, build some good freeways so people can move short distances on car and divert funds mostly to high-speed segregated passenger rail, like Italy and France have been doing for a while.

Passenger and freight have very different demands for optimum railway system design and configuration, therefore they should be segregated as much as possible, for the same reason you have heavy industry parks placed not side-by-side with prime commercial office space locations.

In Europe, they should invest in more freight-only railways like Betuweroute in The Netherlands, to divert to rail freight that can be diverted to rail and freeing up space in freeways for cars.


----------



## SamuraiBlue (Apr 2, 2010)

However you do the math, grinding steel against steel(through friction) adds up to wear and tear and faster you grind and/or pushing it harder against each other the more you grind. (the biggest concern being uneven grinding)
Heat also builds up since traction is a form of friction which may resort to distortion. 
Lateral force produced at corners will also distort the rail.

The reason why Japan places priority on axle load is because of the high frequency of usage averaging at around 5~10 minutes from 5AM to 12 AM for most Shinkansen lines and higher frequency for most commuter lines.


----------



## K_ (Jan 5, 2010)

Suburbanist said:


> Indeed, instead of banning freight they should cut off passenger service in inferior railways (V<140 km/h) and segregate passenger and freight. Then, build some good freeways so people can move short distances on car and divert funds mostly to high-speed segregated passenger rail, like Italy and France have been doing for a while.


I'd like to know where you would put all the freeways we would need to build if we got rid of the Zürich S-Bahn, or the Paris RER...


----------



## K_ (Jan 5, 2010)

railzilla said:


> Screw coupler take twice the man power for any shunting operation, thus making car load operations ineffective. It is also more time consuming to decouple or couple screw couplers. Also it is a very dangerous job. Of course for unit trains it is not so important but as now the couplers are the limit of locomotive power. For gradients pusher or midtrain helpers are needed to not break the couplers. Again distributed power can solve the problem.


Where do you actually get this "twice the man power" figure from? A US style coupler still requires manual intevention to connect the brake hose. The european screw coupler also has the advantage that you can push a consist with it being coupled, making things like "fly shunting" easy. You can even put a banking locomotive at the back without coupling it.
Whitnessing loco changes on the SBB I notice that one man can couple a locomotive in about a minute. Coupling all the different hoses and cables takes up most of that time. I don't think that with an AAR coupler it would be much faster.

The big advantage of the AAR coupler is its greater strength. It didn't prevent car load operations to decline in the US however...


----------



## Rebasepoiss (Jan 6, 2007)

Suburbanist said:


> Indeed, instead of banning freight they *should cut off passenger service in inferior railways *(V<140 km/h) and segregate passenger and freight. Then, build some good freeways so people *can move short distances on car *and divert funds mostly to high-speed segregated passenger rail, like Italy and France have been doing for a while.


I'm 99% sure that the number of people who use commuter trains in Europe every day is far greater than the number of high-speed rail users.

If the railway capacity already exists, why divert people from the railways to motorways which can't possibly handle the additional users without massive widenings? Your idea sounds a "bit" inefficient to me.


----------



## sotavento (May 12, 2005)

railzilla said:


> Japanese trains be it commuter, regional or Shinkansen have a very low axle load compared to Europe and especially to North America. The success of Japanese railway and the reliability of them suggest this is one of the key factors. Axle load is also discussed in the sources about Japanese railways i could find on the web. Many improvements in Japanese railways where to keep the axle load low to an extend that they even use EMUs to transport containers.
> However i haven't found a formula to calculate the effect of axle loads and speed to the wear of the track. For example if a train with 10 tons axle loads traveling at 100km/h, how will an increase of speed or axle load affect the wear on the track.
> I think it increases with the square of the speed so a 200km/h train does four times the damage of a 100km/h one.
> For the axle load t increases with the cubic so a 20tons trains does eight times the damage a 10ton axle load train does .
> ...


hno:

HSR everywhere runs on continuously welded rail with axle loads of 17ton/axle or less ... preferably less than 15ton/axle. 

Japan
0 series = 15,1ton/axle 200km/h (later 220km/h) 
300 series = 11,1ton/axle 270km/h (1992?)
N700 = 11,17ton /axle (for the empty train?) 300km/h + 1,6ton /axle for passenger load (plus tilting)
C751(singapore metro) = 15ton/axle 80km/h
BR c395 = 11,46ton/axle 225km/h 

france
TGV Atlantique = 14,8 ton/axle 300km/h (passive tilt/uncompensated cant)
TGV Duplex = 14,6ton/axle 320km/h (passive tilt/uncompensated cant)
AGC(X76500/Z27500/B81000) = 15,3ton/axle (comuter/regional emu/dmu/bi-mode) 
Z21500 = 14ton/axle 200km/h (comuter)

Italy/Finland/Portugal/others
Pendulino = 13,5ton/axle 250km/h (active tilting)

Spain
Renfe s120 = 14ton/axle 250km/h 
Renfe s102 = 15,3ton/axle 330km/h 
Renfe s103 = 13ton/axle 350km/h


the sweetspot between traction and track wear seems to be somewhere in between 13ton and 17ton ... and one always need to take into acount the passengers weight (most train weights are measured empty).


----------



## sotavento (May 12, 2005)

K_ said:


> Where do you actually get this "twice the man power" figure from? A US style coupler still requires manual intevention to connect the brake hose. The european screw coupler also has the advantage that you can push a consist with it being coupled, making things like "fly shunting" easy. You can even put a banking locomotive at the back without coupling it.
> Whitnessing loco changes on the SBB I notice that one man can couple a locomotive in about a minute. Coupling all the different hoses and cables takes up most of that time. I don't think that with an AAR coupler it would be much faster.
> 
> The big advantage of the AAR coupler is its greater strength. It didn't prevent car load operations to decline in the US however...


























































People tend to make direct comparisons between things where theres nothing to compare directly.


European trains are neither THE TGV and neither solely the chain coupling. :nuts:

EMU/DMU in europe usually have universal shaffie/delner couplers (or any other automatic coupler) ... freight and passenger rollingstock usually have the universal chain coupling because (when coupled with buffers) it's a very EFFICIENT coupling system.

:cheers: 



Suburbanist said:


> Indeed, instead of banning freight they should cut off passenger service in inferior railways (V<140 km/h) and segregate passenger and freight. Then, build some good freeways so people can move short distances on car and divert funds mostly to high-speed segregated passenger rail, like Italy and France have been doing for a while.
> 
> Passenger and freight have very different demands for optimum railway system design and configuration, therefore they should be segregated as much as possible, for the same reason you have heavy industry parks placed not side-by-side with prime commercial office space locations.
> 
> In Europe, they should invest in more freight-only railways like Betuweroute in The Netherlands, to divert to rail freight that can be diverted to rail and freeing up space in freeways for cars.


Freight and passenger traffic can operate in the same route without much hassle ... if a route allows 100/160 km/h running and is not completelly saturated then theres no problem at all. hno:

Over here they are building the 3rd highway and the 3rd direct railway between our bigger cities (the entire 500km long corridor wich they serve has less than half the population of NYC alone) ... passenger traffic doesn't benefit in any way from being thrown into the road. hno: 

The betuwe is an exception ... it's the freight only link between one of europe biggest ports and the interland wich it serves ... just a small freight bipass and nothing more. 



K_ said:


> I'd like to know where you would put all the freeways we would need to build if we got rid of the Zürich S-Bahn, or the Paris RER...


Exactly ... here our comuter routes have between 100k and 300k daily passengers (k= thousands) ... throw them into the roads ??? the 4/6 lane freeways already have their own 100k /200k daily vehicles (and a lot of buses use them). :nuts:



Suburbanist said:


> Before bashing heavy US rail cars, remember the FHA takes a different approach to all passenger rail traffic safety: it aims to make collisions survivable, hence the strong structural requirements for their rail cars.


European safety rules are directed towards survivability of the passengers and avoiding accidents ... american safety rules are directed towards the survivability of the vehicle.

:cheers:
No matter how people claim otherwise it's the truth ...


----------



## sotavento (May 12, 2005)

railzilla said:


> jrtr.net is a good source in general
> Many manufacturers have websites in english
> Wikipedia is also a good source
> Data for N700 is here: http://www.japantransport.com/seminar/JRCENTRAL.pdf and yes i know it is marketing
> ...





> If Swiss railways would use single deck 20m cars they would be in the same range like Japan. But as long as cargo trains even pass through the Bahn Tunnel and the first series of S-Bahn stock is actually a Loco hauled train maybe it just doesn't make sense to reduce axle loading.


Swiss s-bahn are not the only kind of comuter trains around europe ... 



> Japan switched to EMUs more than fifty years ago. And even for freight the maximum is 17 tons. Maybe they just think in longer terms.


Narrow gauge cant cope with higher axleloads ... too much lateral forces and you derail unless you have extra tight maintenance control ... wich in the end eats up any advantage the lightweight/cheaper advantage the narrow gauge could have had in the first place. :nuts:

And by the way ... around here (PT) we switched to EMU's around ... 1926(?) 



> Nobody here really cares if you have to replace the track after 10,20 or 50 years.
> 
> Thats why i started this thread. It seems Japanese favor more axles over higher axle load. The also distibute propulsion to more axles and use relative weak motors. It is a trade off between vehicle maintenance and track maintenance.


Railways are everithing about "_evolution_" and strikes of luck (also called _revolution_) ... 



> Other have been affected by more incidents which where mostly due to broken rails for example several incidents at Harbruecke.
> 
> I agree. Single tickets are rather expensive while yearly tickets are too cheap. Actually most passengers on the crowded Zurich Bern relation use the GA. Many students live at home and travel across Switzerland every day instead of searching a flat where the study. Same for office workers and of course civil servants which have an even lower price. At the end cheap public transit leads to the same effects like cheap car travel. But for politicians it is easier to buy more trains than double the GA price. Which as you say would still be a fair price. The tender is still not decided but SBB asked for a complicated and expensive solution.hno:


Here (portugal) we have 20m long 1500vDC comuter trains since the 20's ... and our narrow gauge is the same size of the UK broad gauge ... so your point is ??? 

:lol:


In fact the loading gauge in the japanese 3'6" gauge is a bad thing ... it prevents them from using one of the advantages of the cant ... 

Italians , Germans , French , british and Ameircans used to run their express trains at 180km/h as early as the 30's ... Japanese were always limited by the gauge issue. 

So while everyone else just "evolved" what they already had (160/180km/h in express trains) the japanese were forced to make a revolution in their railways ... on the other hand everyone was forced to revolutionize their comuter trains (from steam to electrics in the 20's)... japanse railways just evolved theirs like everyone else. :cheers:


----------



## sotavento (May 12, 2005)

railzilla said:


> First freight loses money in Europe, IMHO as long as outdated screw couplings are used it wont change. If you calculate the damages the freight does to the track it gets even worse.
> Second it is correct that the companies which do not own the track simply do not care about it. So they buy cheap raileaters instead of expensive sophisticated locos which are nicer to the track. Thats true for passenger as well as freight. So pricing should not only include tonnage but also some damage factor. There must be a benefit if better rolling stock is used.
> Third freight needs a lower track standard than passenger.
> So it would make sense to ban freight from the most traveled passenger corridors. Track prices are kilometer based but if you price a longer less direct route with a lower track standard is cheaper, the cargo companies will use it. It doesn't matter if a train with bulk takes a few minutes longer. Fast freight would have to use EMU or DMU just like passengers. See the M250 super cargo express form JR freight.
> ...


Magic formula number one = for freight you need sturdy track (capable of servicing freight above 20ton/axle) and locomotives HEAVY enough to put the power into the rails ... so we end up with 20/22,5/25/30 ton/axle locomotives with 300/450/600 Kn of tractive effort in europe/USA ... if japan doesn't manage to cope with such numbers then it's not particularly because of any flaw in european/american railways (south african railways have such heavy rails and uses the same gauge as conventional japanese railways). :cheers:

Magic formula number two = high speed trains use light axle load and raw power (good acceleration) and very little unsprung weight (for stability at high speeds) ... then enters cant , loose allowed cant deficiencies in curves and tilting (for aditional extra speed) ... the only interest in axle load per se is in having the most HIGH axle load that still allows the train to use (and should I say ABUSE) that same cant allowance (and thus the 13/15 ton/axle). 

What matters in the end is that (at least for most of european rail operators) both definitions are compatible with one another ... you can have 25ton/axle freight and 250km/h passenger trains running in a daily basis in the same tracks with a minimum bump in maintenance costs ... 

offtopic: having MORE axles running over a rail is never a good thing ... the tear and wear is always there ... so decreasing the number of axles to the maximum is always a good thing. :bash:


----------



## SamuraiBlue (Apr 2, 2010)

sotavento said:


> hno:
> HSR everywhere runs on continuously welded rail with axle loads of 17ton/axle or less ... preferably less than 15ton/axle.
> Japan
> 0 series = 15,1ton/axle 200km/h (later 220km/h)
> ...


These comparisons are very misleading since the TGV and the RENFE s102/s103 are lovomotive push-pull that have the engine/motor in the front and rear with trailers in between therefore the weight distribution is completely offset compared to actual EMUs with much more even weight distribution.

High axle load on any single axle will result in higher wear and tear and since traction is developed on these axles the wear and tear would be worse.


----------



## sotavento (May 12, 2005)

SamuraiBlue said:


> These comparisons are very misleading since the TGV and the RENFE s102/s103 are lovomotive push-pull that have the engine/motor in the front and rear with trailers in between therefore the weight distribution is completely offset compared to actual EMUs with much more even weight distribution.
> 
> High axle load on any single axle will result in higher wear and tear and since traction is developed on these axles the wear and tear would be worse.


Not quite right


You people are ALWAYS confusing EMU and motorcoach ...



Series 103 is a siemens velaro wich is a m+r+m+r+m+r+m+r EMU (each m unit is a motored car/motorcoach and each r unit has electric components in a otherwise CONVENTIONAL coach)

Series 102 are lightweight talgo trainsets coupled between 2 TRAXX electric locomotives ... so ... yeah ... conventional top'n'tail.

TGV trainsets are push-pull or top'n'tail lightweight trainsets ... 3 cars per trainset actually wich is amusing ... locomotive + articulated set + locomotive. 


Your main error is precisely when you Assume THAT BECAUSE THEY HAVE traction motors in the extremes that they are indeed "conventional" rolingstock ... actually that principle only aplies to the electric talgo HSR trainsets.


TGV trainsets have distributed weight and quite paradoxaly have the same exact weight/load in each bogie ... because instead of the "conventional" 2 bogies per each 25m/27m long coach only have 1 in each 18m long coach (much more space between wheelsets) ... 8/12 motored axles and 14/18 unpowered axles in each TGV (the atlantique have 22 unpowered axles).
Thats purely because the tecnologies available to the french in the 80's only allowed for a massivelly huge transformer so they ended up with 2 powered axles in a transformer motorcoach (a.K.a. locomotive) ... the original idea was for them to have gas turbine and the 2nd bogie would already be shared (at that time it was deemed unsafe to put passengers in the 1st coach in european railways) ... newer 200+ trains in france/spain are just plain COMUTER/REGIONAL trainsets ... and the TGV has gone back to its origins and became the AGV. 


On the other hand the ICE1 was a purellly UBER-POWERED "conventional" HST ... two "evolved" DB120 locomotives and a rack of 14 conventional coaches in betweeen ... ICE2 was a pair of half sets with 1 locomotive and 7 conventional coaches ... the last one having a nose/cabin similar to the locomotive (same principle was followed by swedish X2000) ... and only after some litigations were they allowed to run above 160km/h with the coach in front of the train (british rail just went with the DVT - a end car with no passengers) ... ICE3 was then again a development based on the italian pendolinos (wich were the 1st actual HSR trainsets allowed at more than 160/200km/h with passengers in the first coach) ... and here in the ICE3 a key factor was the tecnological development of transformers small enough to be placed undefloor. 

You seem to neglect almost the entire lineage of european electric/turbine/diesel HST's dating from way back as 1900. :cheers:



Japanese shinkansen are indeed based on the principle of conventional EMU rolingstock ... wich makes them not very different from about 1/2 the european trains around. :nuts:


----------



## Republica (Jun 30, 2005)

my god


----------



## Gadiri (Oct 30, 2009)

Double deck trains with only 17 tonnes per axle (maximum "authorized" in Europe) in a articulated train (18m cars), when others have 15 tonnes with 1 deck in no-articulated trains (24m cars). That's french technology ! :cheers:


----------

