Thursday, October 30, 2008

Pinder v Fox

Russ Pinder's case against Fox Racing Shox (MTB fork manufacturer) is finally underway in the High Court. There are two brief articles about it here and here, and lots of ill-informed argumentation on the STW forum as usual, despite the best attempts of the proprietors to shut down any discussion (see 1, 2, 3, 4, 5). It is interesting to see that 5 years after I worked out what was going on and wrote it all down in simple terms, people still seem to feel the need to make up uninformed nonsense (although I'm sure all climate scientists will be familiar with such behaviour). As I mentioned recently, this stuff is not rocket science, it is just the way that bolted joints work (or rather, how they fail if over-stressed) and has been basic engineering knowledge for decades.

I don't know the details of their case, but for the background to the incident that underlies it you can look here and here. It seems like there should be a verdict early next week. I hope they have done their homework and wish them all the best.

Friday, October 24, 2008

It's deja vu all over again

As Yogi Berra is reputed to have said (I'm sure he can't be the only one).

This caught my attention in the news yesterday:
Passengers at risk from track design flaw

A design flaw found in thousands of places on the country’s rail network is putting passengers at risk of a catastrophic derailment similar to the Potters Bar and Grayrigg disasters, according to a secret analysis by rail safety inspectors.
It says that the joint “may not withstand normally encountered forces imposed by the operating railway, resulting in the potential for loose fasteners and consequent changes to the configuration of the points leading to further points degradation and subsequent train derailment”.
A source close to the investigation said: “We should not just be relying on track workers to spot loose bolts in time. We need to stop the bolts from coming loose. This is about making sure that the points are fail-safe.”
Sound familiar? Of course, it's exactly the same process that I uncovered with quick-release failures on disk brake-equipped bicycles - an underspecified bolted fastener working loose due to an applied load that exceeds the capacity of the design.

Here is the full report on the Grayrigg crash. A few excerpts:

The fasteners in the third permanent way stretcher bar joint failed by unwinding. This occurs when the applied load exceeds the clamping force on the joint. The RAIB has concluded that, in this case, such loadings were a result of the passage of trains.
The RAIB has concluded that the design of the joint between the permanent way stretcher bar bracket and the switch rail at 2B points, and of other similarly configured points, was such that it could have been subjected to forces beyond its design capability and therefore the points system had significant reliance on regular inspection and maintenance to maintain safe operations.
The RAIB concludes that this incomplete understanding of the performance of S&C with non-adjustable stretcher bars, and the relationships between its design, usage, loadings, inspection and maintenance, led Network Rail to consider that the risk associated with the design was low and was being adequately controlled. This also resulted in an absence of clear and properly briefed standards for the setting up and adjustment of S&C.

[S&C - switches and crossings, a generic term for various railway track junctions]

There is lots more to wade though for anyone who is interested. But there is hardly any need. It is hardly rocket science - it took me literally seconds to find out what I needed to know via Google and this web site, once I guessed at what was going on back in 2003 (in relation to disk brakes). It is worrying to think that there are supposedly qualified engineers out there who don't know this stuff like the back of their hands...

Thursday, October 23, 2008


I know it's been some time since I blogged anything. I'm a bit bored of it, to be honest. But last weekend we had a bath, so I thought I would share a picture or two. We do have a bath at home, but it doesn't look (or smell) like this open-air sulphurous pit at Azohara Onsen:

Actually we had several baths in the three days we were up in the mountains - that was the most spectacularly sited one though, high up in the Kurobe Gorge 5h walk from the nearest access (a little narrow-gauge rattling train). The autumn leaves were perhaps just a little short of their peak colour, but the mountain huts are about to close for the winter (in fact one of them will be completely dismantled to avoid snow damage) so we thought we had better take advantage of the good weather while it lasted.

It was pretty spectacular but a little difficult to photograph with the high contrast. And in a month or two we'll get to enjoy a second dose of the autumn colors down here in Kamakura...

Wednesday, October 01, 2008

Another from the department of "you couldn't make it up"

Former Prime Minister Junichiro Koizumi on Saturday formally announced his intention to retire from politics and said he will not run in the next House of Representatives election.

Koizumi, 66, also named his second son and secretary, 27-year-old Shinjiro Koizumi, as his heir apparent to the Kanagawa No. 11 district.

Koizumi did acknowledge criticism about giving his political base to his son, saying, ‘‘I too was criticized for being a third-generation politician. However, no-one will be able to accuse my son of such a short pedigree.’’

Shinjiro is now 33rd in line to the throne Prime Minister's Office and his inauguration is scheduled for early 2045.

[Editor's note: not all of the above is strictly true. Scarily, most of it is.]