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Cheung L.L.K.,University of Cambridge | Soga K.,University of Cambridge | Bennett P.J.,University of Cambridge | Kobayashi Y.,University of Cambridge | And 3 more authors.
Proceedings of the Institution of Civil Engineers: Geotechnical Engineering | Year: 2010

A trial strain-monitoring system using Brillouin optical time-domain reflectometry (BOTDR) technology was set up to monitor joint movements in the concrete tunnel lining in an existing London Underground tunnel. The BOTDR strain sensor system allows the measurement of strain distribution along an optical fibre using the reflective technique, requiring access to only one end of the fibre. Measurements were obtained by a strain-sensing optical fibre installed along the tunnel lining. The joint movements were captured by measuring the strain along the fibre across the segment joints. The results show that there is good agreement between the joint movements evaluated by the BOTDR strain sensor system and those by conventional vibrating-wire strain gauges. Whereas conventional strain measurement gauges monitor the strain variations at discrete locations, a BOTDR strain sensor can provide a continuous strain distribution of the tunnel lining. The results demonstrate the practicality of using the BOTDR strain-sensing system to monitor the movement of tunnel linings. Source

Bennett P.J.,University of Cambridge | Kobayashi Y.,Railway Technical Research Institute | Soga K.,University of Cambridge | Wright P.,Tube Lines Ltd
Proceedings of the Institution of Civil Engineers: Geotechnical Engineering | Year: 2010

A hybrid wireless sensor network has been developed for structural monitoring of transport tunnels. The system combines the advantages of wired and wireless sensing to simplify and speed up installation. The wireless modules are based on low-cost sensors for inclination or displacement, and temperature and humidity. These are combined with a commercial radio module to eliminate the need to install cables around the tunnel. The modules report readings back to a gateway installed on the wall of the tunnel, automatically relaying the readings from other modules as required. The readings are transmitted to the surface along cables that can be quickly and easily installed in the cable trays running along the walls of the tunnel and up the closest vent shaft. From the surface the readings are sent to a server via the mobile phone network and made available in real time on a web page. The results of a trial installation on the London Underground Jubilee line are reported. Source

Bourne A.,Tube Lines Ltd
IET Seminar Digest | Year: 2012

This paper considers the importance of managing requirements as one of the keys to ensuring successful systems development. Sources and types of requirements are discussed along with how they are expressed and their place in the system lifecycle. The use of tools to assist with requirements management is considered and some of the pitfalls to avoid are given. The purpose of the paper is to provide an introduction to the subject, with a particular bias towards railway signalling system requirements (although the principles hold good for any type of system). Source

Palfreyman T.W.,Parsons Brinckerhoff | Moore L.C.,Tube Lines Ltd
IET Seminar Digest | Year: 2010

Introducing a Transmission Based Train Control signalling system on London Underground's Northern Line facilitates an appreciable increase in train service frequencies, impacting the existing 630V DC 'four rail' traction power system. Extensive operational and traction power simulation modelling was undertaken to investigate train voltage regulation especially under electrical outage and perturbed operating conditions. Traction power system upgrade options were developed comprising 'low loss' Composite Conductor Rail (CCR), increasing system voltage to 750V, and parallel cabling. The upgrade options were evaluated in terms of equipment quantities, costs, installation programmes, and energy losses (including tunnel environmental impacts), and a single option taken forward for implementation. Rail, Traction, Simulation, Modelling, Energy. Source

Wodehouse R.G.,Tube Lines Ltd
Structural Engineer | Year: 2011

This advisory paper identifies and explains those specific constraints relating to designing within existing London Underground (LU) stations and adjacent to the track and the resulting preferred method of construction. Key design parameters are examined and the comparative significance of other disciplines is discussed. The main outcome being that in heavily restricted sites with exacting design and operating tolerances from lifts, escalators, and track, knowledge of plant operating requirements and their effect on design is essential. These parameters are examined along with the significance of other disciplines. © R. G. Wodehouse. Source

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