Kato curved bridge

[velotrain]

I just received the Kato curved bridge today,

 

20-823            http://www.1999.co.jp/eng/10420312

 

 

The actual support pillar is disappointingly short, and the bottom section in their marketing photo is not included, or the round base "collar" that is shown.  Perhaps they are developing this for future release, but that doesn't absolve them for showing the bridge with components that aren't actually included in the set.

 

I'm attaching a photo of the package, along with one of the cast pillars on top to illustrate the difference.  The actual pillar is only about 2/3 the height that they suggest on the box and in other marketing photos.

 

 

 

 

 

[katoftw]

I noticed that when they first released the photos.  And I'm pretty sure I mentioned it in the Kato New Releases thread.

[velotrain]

Not that I can find - would you have a message number?

[katoftw]

It would only be a few pages back.  As the discussions were only recent.  Something about making "add-ons" to the pillars like in the Kato promo pictures.  As Kato's pillars are only listed as 50mm height.

Edited December 9, 2016 by katoftw

[ToniBabelony]

It's not deceptive, as the description underneath the poster claims it's a diorama and may not depict the actual product. Furthermore, on the Kato website the pillars are photographed as they are released as the actual product you buy, stating at least six times the pillars are 50mm high: http://www.katomodels.com/product/nmi/deck_gutter.shtml

[velotrain]

It's not deceptive, as the description underneath the poster claims it's a diorama and may not depict the actual product.

 

I don't know what the Japanese text says, but the English is: "Train and diorama are not included in this set"

 

The box does say "Curved Bridge Set", with no indication that the bridge is not as shown.

 

I think most reasonable people would consider the pillars part of the Bridge Set, and not the diorama.

 

Sorry, but I don't go to the Kato website, and get my info here and from the retainers that I purchase from.

[katoftw]

I would respectfully disagree.  Most would have noticed the differences between the diorama and actual product available by comparing pictures.  My younger eyes are probably better than yours.  Maybe that is why I noticed the differences. 

 

I think your frustration comes from feeling you didn't get what you thought you were to get versus what you actually should have got.  I don't think the marketing of the product was misleading either.

 

If you are unhappy with the product your received, you can always on sell it on ebay etc to recoop some money.  Doesn't fix your frustration, but at least you'll get some coin back.

Edited December 9, 2016 by katoftw

[velotrain]

You're right - but I'll just build my own pier extensions, so the bridge will be closer to the proto height.

 

I think what happened was that actual product photos became superseded by Kato promotional photos which suggested that the product piers were higher than actual. 

I suspect that after those were available, I didn't go back and look at product pictures.

[kvp]

Actually, the Hobby Search info page has the actual photo of the product without the dirorama additions on the product page (1st picture under other pictures). Also they wrote down the height of the columns. I think this is the case when you are meant to at least look at all the included pictures before buying something.

[velotrain]

My issue isn't so much with the product or retailers, but Kato's post-release marketing.

 

[medusa]

BTW, the catenary looks interesting. Is that included in the set? Never saw it before.

[velotrain]

If you mean the poles, then yes.

[Ken Ford]

velotrain, are the bridge sections with the curves physically wider than the straight sections? I love the look of this bridge, but have been trying to focus on Nj instead of 9mm N (not that anything is getting done...)

[kvp]

On the ends, the railings are exactly where you find them on the straight variant. Between those points, the railing is straight, making the bridge wider. The loading gauge is effectively not increased though.

[velotrain]

Ken - No real difference.  Essentially, all they've done is put a curved track on a straight bridge.

 

I'm going to disagree with kvp though, as the below photo shows that the railing on the straight bridge juts out a little (reason unknown), so it is actually a tad wider than the curved bridge.

 

However, the ties do overhang just a little bit more on the outside of the curved bridge.

 

You could easily remove the tracks if you wanted to convert to Nj (screws on the straight, spring clips on the curve), although you would want an equally wide radius curve - OR, you'd need to shorten the bridge segment.  The outer rail on the curved bridge is just barely over the beam at the widest point of the curve - which is likely how they selected the radius.

 

 

[kvp]

Isn't Nj means 1:150 N gauge? You might be thinking of Njm or N scale japanese meter gauge? (1:150 meter gauge)

 

Btw: i was talking about the ends of the railings being at the same location on both bridges

[velotrain]

Isn't Nj means 1:150 N gauge? You might be thinking of Njm or N scale japanese meter gauge? (1:150 meter gauge)

 

Btw: i was talking about the ends of the railings being at the same location on both bridges

 

I was just quoting Ken, "Nj instead of 9mm N"

 

 

"On the ends, the railings are exactly where you find them on the straight variant. Between those points, the railing is straight, making the bridge wider."

 

Yes, I get that you're saying the railing ends are aligned, but you seem to be suggesting that the curved bridge is wider because the railing is straight.  Perhaps you meant the opposite? 

[kvp]

The bridge structure itself is wider at the middle due to the curve and the straight railing, but the effective loading gauge is the same.

[velotrain]

The bridge structure itself is wider at the middle due to the curve and the straight railing, but the effective loading gauge is the same.

 

I have no idea what that means - in my experience bridges are generally the same width throughout their length.  That has somewhat changed in the last decade or two with "designer" bridges, particularly for pedestrian use.

 

Regarding the Kato bridges under discussion, the plate girders on the curved bridge are slightly farther apart from each other (19mm vs 17mm - outer edges) than on the straight bridge, but both bridges are 29mm wide overall, from the outside of the ties to the outside of the railing on the other side.

 

The railing on the straight bridge has 2mm wide and 3mm long "notches" on each end (as seen in the previously posted photo), but for the rest of the bridge the walkway is actually wider than it is on the curved bridge.  The railing and the outer edge of the ties are parallel for their whole length on both bridges, so how could the curved bridge be wider at the middle?  It is in fact a straight bridge in structure, but with curved rails.

 

If you are speaking in comparison to the straight bridge, the railing and the outer edge of the ties are also parallel for their whole length, and both bridges share a 29mm overall width.  Since the notches in the railings comprise less than 1/20th the length of the straight bridge, you could say that the curved bridge is in fact wider at the extreme ends (3mm each), but saying that it is wider in "the middle" just doesn't agree with the measurements.  I can understand why you might think so, but that isn't how Kato designed these bridges.

 

Do you have the actual bridges in front of you? 

 

Based on your statement, I now suspect you're working on a purely theoretical basis.  If the railing is straight, surely the distance from it to the outside of the curve must be greater than from the railing to the outer rail on the straight track.  That is indeed true, but you're not allowing for the wider walkway on the straight bridge, or the shorter distance from the outer rail to the edge of the ties at the widest point of the curve.  I just realized that the notches in the walkway of the straight bridge are exactly what allows Kato to achieve this.

 

 

 

 

[kvp]

So the short outer ties and reduced walkway width result in the same overall superstructure width and only the main beam is wider due to the unijoiners needing more space at the angled ends. This difference is compensated by the notched railings and the same tie end - beam centerline distance on the railingless side.

[velotrain]

There is no one main beam that is wider - there are a pair of plate girders that are spaced more widely apart.  This may well be for the unijoiner, but I'd also like to think that it correlates to the supposed structural engineering need to support a wider cross section of track (rail).  The notched railings allow a seamless transition at the rail join.

 

I'm suitably impressed by the Kato design engineering.  Realizing they needed to space the plate girders more widely, they had to figure out how to align both the rails and the railings.

 

> "the same tie end - beam centerline distance on the railingless side." 

 

That actually isn't the case - this distance is 2-3 mm greater on the curved track bridge, measuring from the middle of the plate girders, in the middle of the bridge.

[Ken Ford]

Isn't Nj means 1:150 N gauge? You might be thinking of Njm or N scale japanese meter gauge? (1:150 meter gauge)

Btw: i was talking about the ends of the railings being at the same location on both bridges

It's generally used to describe 1:150 on 6.5mm track. It's actually too narrow, but for representing 1067mm Japanese railways it looks a lot better to my eye than does 9mm.

[kvp]

I'm suitably impressed by the Kato design engineering.

It's nice but not exactly rocket science. If you put a curved piece of track between two already made straight brides and connect the inside plate ends with a straight line, then add its outside pair far enough to cover the joiners, then add the cross pices to form the main beam. This will be slightly wider than on the straight bridge. The railing is just a straight line between the ends of the two straight bridge pieces. The only interesting part are the ties, that are sized in a way that on one side they reach the walkway and on the other side are long enough to have the tracks covered. What is funny is how the result gives a similar overall width in the center than the straight bridge with the protuding walkway. What is also interesting is the small difference between the radius of a turnout curve and the bridge as logically, they should have been equal. (for legacy reasons although the bridge fits better with the 33mm logic)

[velotrain]

I've been thinking that one way to raise the piers is to follow prototype practice and simply add wide reinforcing collars under them.  The included pier is 3/4" diameter at the bottom, so a 1" dowel would work for this, although there are no doubt various capped plastic castings or styrene/? tubes that could be substituted.  These particular ones look far from new, and even appear to have more recent patches applied to the upstream sides - where they would be battered by floating trees and perhaps riverbed boulders moved along by the spring torrent, as suggested by the collection on the far shore.  You could age the Kato piers, and finish the collars as more newly poured concrete, to create contrast and visual interest.

 

I've seen other examples of this, including this selective application on the Konan, which nicely illustrates what I was saying about the visual ages of the concrete.  As is clearly the case here, this treatment is exclusively applied to piers that are normally subject to water flow - perhaps just in high-water seasons, when the force against them would be greatest.  The untreated piers on the bank may be subject to inundation in a (rare?) flood situation, but would incur much less pressure than piers in the main river channel.  I really like the cantilevered catenary support used on both these lines (perhaps the first image is Konan also?), and perhaps we can hope that Kato will someday produce it to go with their existing latticework poles.

 

Lastly - a third example in winter.  Although - based on the coloration, these rings could be original equipment, but that wouldn't stop you from doing something similar.  I take the colored bands on the nearest pier to indicate increasing levels of concern based on water level.

 

 

 

 

 

 

 

 

 

[velotrain]

What is funny is how the result gives a similar overall width in the center than the straight bridge with the protuding walkway.

You keep mentioning the "width in the center". Do you actually know of any "curved" (superstructure and/or rails) railway bridge where the width is not consistent over the entire length of at least that section - if not the whole bridge? Sound engineering would seem to dictate that the structural width should remain a constant, and this is true on masonry viaducts, as well as steel bridges of all designs. It even appears to be true on this quite unusual S-curve wooden bridge - which is undoubtedly located in a country with minimal standards for governmental inspection of infrastructure. Edited December 12, 2016 by cteno4
Copyrighted image removed