VSJ – July 2008 – Symposium Report

In an uncertain world, it’s nice to know that there are some things you can rely on. One of them is that Paul Lynham will write the report on the IAP’s Spring Event. However, there is a change this year. We can’t introduce him just as ‘Council member’ any longer, because he is now Vice President of the Institution. Congratulations, Paul!

This year’s symposium was held at the London Transport Museum, in Covent Garden. Mike Ryan,  the IAP’s Director General, welcomed all the delegates and called upon John Weller, IAP Treasurer, to introduce the first speaker, David Broughton.

David had been a colleague of John’s in the RAF and left the service as a Group Captain. He is currently the director of the Royal Institute of Navigation. David’s presentation was entitled “Trials and Tribulations of Satellite Navigation” and started with the question – “Satellite Navigation – where are we now”?

In 1968 it was accurate to 10 miles. By 2000, this was down to 10 metres, a 2000-fold improvement. There are twenty one (plus three spare) satellites used for GPS, with each satellite having 3 of every piece of equipment. The satellites have an inclination of 55 degrees at an altitude of 20,200 Km and a 12-hour orbit. The equipment aboard the satellite creates pseudo-random noise (PRN) at 1 MHz. Correlation detection is used to establish synchronisation between the receiving equipment and the satellite.

The services that can be provided at a given point are governed by the number of satellites that can be seen from there. A single satellite merely gives the time. Two provide a position line. Three are required for a 2D fix and four will give a 3D fix.

Originally, accuracy was deliberately degraded to 100m to avoid misuse. In May 2000 the Americans declared that degradation was to be removed, so now accuracy is 10 to 15m with raw GPS. A technique called differential GPS can be used to improve accuracy still further, so that the error can be as little as 3m. GPS has difficulty working inside buildings, but more sensitive receivers are being devised. Similar problems are experienced when working near trees. Although very rare, a further difficulty is called satellite erosion, where a satellite gives false readings.

There are alternatives to GPS including GLONASS/Galileo, LORAN and Low Frequency Systems, mobile telephones and WiFi amongst others. The GPS signal is very weak, since the satellite transmitters have a power of only about 50 watts. By the time it reaches the Earth’s surface, that’s attenuated to about 5×10-17 watts. So an intelligently placed jammer on the ground emitting just 1 watt might knock out receivers within an area of 1600 Km2 or more.

As with other technologies, it is so easy to turn off your brain when using satellite navigation systems. David showed a slide of a speed boat that had crashed into a pillar in the sea, precisely because of the accuracy the system! A famous incident involved the cruise ship Royal Majesty, which ran aground because the GPS antenna cable had become detached, but the navigators disregarded all other navigational inputs, believing the (no longer operational) GPS system! Villages with narrow roads are also putting up signs telling large vehicles that roads are unsuitable for them, even though the systems they use will advise that route.

The next speaker was Philip Bly, who is an independent transport consultant. He started his career lecturing in solid state physics in Canada and then joined the Transport Research Laboratory at Crowthorne in 1971. He became Head of the Vehicles Group in 1988 and was appointed Director of Research in 1992, before becoming a consultant four years later. His topic was “Driverless Cars – Personal Rapid Transport”.

Phil gave a brief history of public transport in London, starting in 1829 with Shilibier’s horse-drawn omnibus, to 1910 and the internal combustion engine, to 1950 and the RouteMaster bus, until now with hydrogen fuel cell buses.

Although the technology has moved on greatly, public transport operations have not. You still arrive at a location designated as a pick-up point. There you wait until the transport arrives. You board and find a seat. Along the route, the vehicle will stop at intermediate points, either due to traffic or to pick up passengers. At your nearest destination point, you leave and may transfer to another service, which will iterate through the process again.

Phil posed the question “Does it have to be like this”? Although a taxi is convenient,  it’s very inefficient in terms of passengers per mile with typical values of less than 1. Also the average speed of urban transport is a mere 15Kph. In London, it’s only 6Kph and has been for the last century.

Personal Rapid Transit (PRT) vehicles will wait for you, will take you non-stop to where you want to go, without transfers, in an environmentally friendly manner and at low cost to boot! They use a series of dedicated one-way guideway networks, with off-line stations, so there are no intermediate stops. This system aims to have at least one empty vehicle in each station all the time. The concept originated in the 1970s and there is a working system in Morgantown, West Virginia. However, this system is not strictly PRT as each car can take 16 passengers. It has had no problems since it has been in operation.

Phil then went on to talk about the ULTra project (Urban Light Transport). It started in 1995 with a prototype developed by 1999. In 2000, permission was given to use a test track in Cardiff. Each car has 4 seats, is battery operated, travels at 40Kph, will run at a 2-second headway and is therefore efficient with low energy (3Kw) and low emissions, as well as being quiet. It is a passive vehicle, with a 2m wide floor at 45cm deep when elevated. It is prefabricated so is cheap and flexible to build and in reality is technically simple. The passengers get in, take a seat and say where they would like to go. The vehicle has an internal map and uses a variety of inputs for guidance, including lasers, beacons and dead reckoning.

The cost of the system is around £3.5 million/Km and has a capacity between 900 and 2500 passengers per hour. Its use gives a 70% carbon benefit over buses and 50% over cars. Even though trials have been taking place in Cardiff for several years, with many people interested, nobody seemed to want to be the first to implement a real installation prior to BAA. They were so impressed that they purchased a third share of ATS (the company developing ULTra). BAA are building a pilot system at Heathrow airport, with the first roll-out as a shuttle, rather than a network, to ferry passengers from car park to terminal. However, after the system is fully tested in the autumn or winter of this year, it is planned to become the core transport system around the airport on a network. Plans are already in place to put four tracks in two bore holes to the central terminal. Further information is available at www.atsltd.co.uk.

Tom Hohenburg, the marketing consultant to the IAP, introduced the final speaker, Ian Arthurton. Ian is chairman of the London Transport Museum and has had a long and varied career with London Transport. The green light had just been given for the Victoria line to be built when he first joined and he was responsible for installing test equipment in the carriages. The equipment is still under the seats 45 years on! Later, he was appointed Operations Director of London Transport, retiring in 1995.

The museum has been transformed by a massive refurbishment that took place between September 2005 and November 2007. This cost £22m of which £9.5m was a grant, with the remainder being raised by the museum and its friends.

The original building was established as a flower market in 1870 and continued in this use until the late 1970s. The building, which is grade II listed, was effectively a large greenhouse. The plan was to improve the humidity and temperature during the refurbishment and use photovoltaic cells in the roof.

During the refurbishment, a resident artist captured many interesting events, such as the removal of trains at the start and the lifting of vehicles into the mezzanine spaces nearer the completion. These drawings are on display in a gallery within the museum and prints are available for purchase.

The museum also has satellite premises in west London where a large number of buses and trains are stored.

London Transport Museum Friends is an organisation that was set up for people interested in transport in the capital. It has 2500 members who are kept informed of the developments in public transport. They provide volunteers to help operate the museum. The Friends have their work cut out in archiving a huge range of artefacts, recording oral history through interviews and raising funds for the museum.

After Ian finished his interesting presentation, he escorted the delegates on a tour of the museum, which houses a varied range of horse-drawn vehicles, taxis, buses, trams and trains amongst other interactive displays. Finally, delegates were taken to Carluccio’s Italian restaurant for a generous three-course lunch with wine and plenty to talk about.

[Interesting project or development? Let us know at eo@iap.org.uk!]

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