Japanese train design

[kvp]

Looking at the videos of the newest E7 sets I wonder about the design of various japanese trains. Today's commuter trains have the no nonsense box on wheels look and I feel this is a good style for them. On the other side shinkansen have a rather different style with their long noses and tiny windows. Interesting is that these two styles almost never mix. (I don't count joyful trains as they are usually one off) In europe high speed and commuter trains have a very similar design. Just look at a railjet, ice or tgv and you can see the similarities with a desiro or a flirt. They all have the now standard rounded nose and large windows, even though the desiro is a branchline dmu. In japan the difference in nose forms is understandable, since for commuter trains the best space utilisation and train to train connectivity is more important and for the shinansen noise and pressure control is a priority, but the windows are really different. The only exception seemed to be the 400 series, where large panorama windows were used. Is there a cultural or an engineering reason for this?

 

Another thing is the use of fixed sets on the shinkansen networks. Sets are almost never changed outside of bigger overhauls, so the use of jackobs bogies would be a viable option to increase ride smoothness, decrease wheel noise and avoid complex dampers between cars. However most trains is japan use the conventional two bogies per car layout, except for odakyu where many romancecar sets used jackobs bogies and some one off prototype trains. Is there a reason for this?

[bikkuri bahn]

Designs are almost always a result of engineering and service requirements, not "cultural".  Windows are small on shinkansen because of the numerous (narrow) tunnels on shinkansen lines, compared with European HSLs.  Jacobs bogies are not really the standard on high speed train sets, just those built by Alstom.  In Japan, standard layouts are preferred for ease of maintenance, as rolling stock availability is a cornerstone of Japanese railway operations. Also the diversity of rolling stock on Japanese railways is part of the tradition of custom building for individual customers, though this is changing, led by JR East/JTREC. In the end, the Japanese railways use designs that best fit what they need, not what some European builder declares as "the world standard" but may be a case of forcing a square peg in a round hole.

Edited December 13, 2013 by bikkuri bahn

[ToniBabelony]

It might surprise you, but Odakyu only has four trains with jacobs bogies (2x 7000 series LSE & 2x 50000 series VSE). The rest is all conventional 2-bogie sets. It's not a lot.

 

Next to that, all Enoden trains have jacobs bogies (not counting the single 100 type), and three Fukui RR 200 type trains. Trams don't really count, do they? ;)

[kvp]

So I guess the jackobs bogies are currently out of fashion everywhere.

 

Windows are small on shinkansen because of the numerous (narrow) tunnels on shinkansen lines, compared with European HSLs.

Could you explain this to me? I don't really understand why a narrow tunnel would mean small windows are needed. The special engineering behind shinkansen trains is not really understood on most parts of the world, except maybe the requirements for the special noses. Most European and US high speed trains look like the nicer styled limited expresses in Japan.

 

Trams don't really count, do they?

They do, but they are a whole different world and have to get into places (like tight city corners) where normal trains rarely go. (except a few exceptions in Japan) Sadly jackobs bogies are also increasingly rare in modern trams too.

[200系]

kvp,

 

but the windows are really different. The only exception seemed to be the 400 series, where large panorama windows were used. Is there a cultural or an engineering reason for this?

 

The original 0系 production cars (batch 1 till 21, built from 1964 till 1976), the 0系0番台 had large 'picture windows' as well which where based on the big windows introduced by the 151系 and subsequently used by all J.N.R. Limited Express units (the 0系 windows where shaped slightly different though, and used triple glass as opposed to double) as can be seen on this picture:

 

 

These large windows proved to be expensive to replace when cracked, which happened relatively frequent during winter months. So when J.N.R. was working on a replacement for the original 0系 cars, which where up for replacement around that time, it was decided to replace the large windows (1460mm for standard cars, 1870mm for green cars) with small windows (630mm and 850mm). At the same time the seating arrangement was also changed from a vis-à-vis (facing each other) to a coach (facing the back of seat in front) configuration with movable seat backs, the small windows allowed for every seat to be aligned with a window. These changes, among others, where first implemented on the 0系1000番台 introduced in 1976 and produced till 1981 (batch 22 till 29) which with the exception of 3 new 16 car formations (N97~N99) where all built to replace life expired 0系0番台 cars, creating mixed small/large windows formations from 1976 till 1998 (last being 16 car Yk formation, Yk22) and 2000 (last being 4 car Q ,formation Q2).

 

0系1000番台 (37形):

 

 

The last batches of 0系 built (batch 30~36, built from 1981 till 1986) , or the 0系2000番台 introduced a new interior and with that an increase in seat pitch (from 940mm to 980mm) similar to the then new 200系 being built for the Tōhoku/Jōetsu Shinkansen, they also introduced slightly wider windows (720mm and 900mm) to accommodate the pitch increase

 

0系2000番台 (if you look closely, you can see the size difference):

 

 

 

The only exception seemed to be the 400 series

 

there where/are a few more shinkansen series using large windows then just the 400系 :

 

- 100系, with the exception of the prototype formation X1 (former X0) which still had the 0系2000番台/200系 style small windows, the 100系 reverted back to the same window shape and size of the 0系0番台 for all production formations (X, G and V).

-200系, while all original cars where all built with small windows, the twelve 1989/1990 built 248形 and 249形 double decks cars (6x 248形, 6x 249形) built for the newly formed H formations, all had large windows.

-E1系, all 6 formations had large windows, though with a thin window still in the middle.

-E2系0番台 J formations, while the original 8 car formations all had small windows, when extended to 10 car formation in 2002, the 2 extra cars (1 E225-100形 1 E226-400形) all have large windows similar to the E2系1000番台 and E1系 cars

-E2系1000番台, large windows with the exception of the E215-1000形 green car.

-E4系 same as the E1系

 

 

so the use of jackobs bogies would be a viable option to increase ride smoothness, decrease wheel noise and avoid complex dampers between cars. However most trains is japan use the conventional two bogies per car layout

 

The conventional layout does have a few advantages as well:

 

- Lower axle loading, as there are more axles to support the weight of a car. This also means reduced track maintenance.

- The ability to add traction motors under every car, without the need for complex engineering solutions.

- The ability to place up to 4 traction motors per car, this adds additional tractive effort acceleration and reliability (enough spare power to keep the train going if a traction motor malfunctions). though nowadays shinkansen are mostly using 3M 1T blocks of cars (3 motorized cars, 1 trailer).

- The ability to keep using the 25m car standard set by the 0系

- The ability to easily split a formation for maintenance

- The ability to easily reform a formation when the need arises, for example with the 0系, 200系 and 100系 as well as the 500系 more recently.

 

As for ride smoothness, I personally think this is hit or miss with articulated units, they can be reasonably smooth like the TGV (though to be fair, I found the shinkansen smoother all around, and the ICE3 felt smoother then the TGV at speed) but they can be horribly rough as well , good examples (in my view) are the Dutch class 1946 stock (Mat'46, retired in 1983) and the much newer German BR425, both having the same pronounced lateral sway, especially when sitting above the Jacobs trucks. While the rough ride quality of Mat'46 could be attributed to more then just the Jacobs trucks, especially concerning it's age and story, I find it more worrying that a much newer train has some of the same problems as it's 60 year older sister.

 

The above is just my opinion, but I don't think it's fair to say that Jacobs trucks are necessarily smoother, nor that they are necessarily inferior. Each configuration has it's strengths and weaknesses and can be used effectively.

 

 

-Sander

Edited December 13, 2013 by 200系

[Densha]

As for ride smoothness, I personally think this is hit or miss with articulated units, they can be reasonably smooth like the TGV (though to be fair, I found the shinkansen smoother all around, and the ICE3 felt smoother then the TGV at speed) but they can be horribly rough as well , good examples (in my view) are the Dutch class 1946 stock (Mat'46, retired in 1983) and the much newer German BR425, both having the same pronounced lateral sway, especially when sitting above the Jacobs trucks. While the rough ride quality of Mat'46 could be attributed to more then just the Jacobs trucks, especially concerning it's age and story, I find it more worrying that a much newer train has some of the same problems as it's 60 year older sister.

 

The above is just my opinion, but I don't think it's fair to say that Jacobs trucks are necessarily smoother, nor that they are necessarily inferior. Each configuration has it's strengths and weaknesses and can be used effectively.

Second that. The Dutch SLT type, derived from the BR425, doesn't really have very good 'ride comfort/quality'. The types from the '70s and '80s with conventional bogies are better in that way. The ICE3 felt smoother than the TGV to me as well, and I don't like the small cars of the TGV because they feel cramped in multiple ways, which is a direct disadvantage of the use of jacobs bogies.

But more than that I'm always questioning myself why they would actually even use jacobs bogies on conventional trains. I have never found the answer (yet). I just can't comprehend it because normally you only use them when you need to go through tight curves but that is certainly not the case with normal heavy rail.

[kvp]

The original 0系 production cars (batch 1 till 21, built from 1964 till 1976), the 0系0番台 had large 'picture windows' as well

 

Wow, thank you! You really know all the types and subtypes. Imho the original series 0 cars looked much better, regardless of the window cracking problem, but it's understandable that they wanted to avoid the problems. I didn't know about the other cars either and that means I still have much to learn. I think the smoother ride on japanese trains can be accounted to the much better tracks. Even the german ICE had some problems when they were run over the TGV network. The br425 problem is caused by the hunting of the trucks and that is caused by the incorrect wheel profile combined with the inadequate damping in the suspension. This can be so serious that the brake disks continously hit the pads at full speed even with fully released brakes, causing a bumpy ride.

 

But more than that I'm always questioning myself why they would actually even use jacobs bogies on conventional trains. I have never found the answer (yet). 

 

The idea was that the shorter cars with less overhang on the outside could be wider and the train is less likely to jackknife in case of a derailment. Besides the french, many german and swiss designs use them, for example the siemens desiro railcars (following the plans of the flying hamburger), the bombardier talents and the stadler flirts. All units are commuter trains with motors only under the end sections and a very lightweight low floor construction. (like a tram) Even the tgv has motors only in the 6 non jackobs bogies. It's true that maintenance is harder, since usually they have to jack up the whole train. This layout along with locomotive hauled push-pull stock (railjet) is very popular in hungary. Considering the differences between the two train networks, the japanese seem to be doing something (or everything) better.

[ToniBabelony]

Found another odd one by the way. The Nishitetsu 500 type with three cars on jacobs bogies:

 

[bikkuri bahn]

Found another odd one by the way. The Nishitetsu 500 type with three cars on jacobs bogies:

There was quite a lot of experimentation by the private railways in the post war era (though actually the 500 type was introduced in 1943!)- they were much more willing to try new designs than JNR, though the introduction of the 101 series and it's subsequent success and influence on rolling stock design put an end to dabbling with quirky designs by most lines.

 

Speaking of Nishitetsu, there is the 313 type (introduced 1952), which was the first monocoque trainbody design in Japan, and still in use: