Tube Lines Ltd

London, United Kingdom

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London, United Kingdom
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Cheung L.L.K.,Geotechnical Engineering Office | Cheung L.L.K.,University of Cambridge | Soga K.,University of Cambridge | Bennett P.J.,University of Cambridge | And 4 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.


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.


Murphy J.,Tube Lines Ltd | Lowten M.,Thales Rail Signalling Solutions | Hope K.,London Underground Ltd
Rail Human Factors: Supporting Reliability, Safety and Cost Reduction | Year: 2013

The Jubilee Line was upgraded to a new Automatic Train Control system. Like other complex systems it has a large alarm system. London Underground's Universal Human Computer Interaction standard (1-218) mandates the use of EEMUA 191 for new alarm systems on its network. Many things were learnt about the application of EEMUA 191 during the Jubilee Line Upgrade Project. The project did benefit from the guidance but there were some areas that were not entirely useful for a rail installation. This paper discusses the nature of the project, the train control and alarm systems selected and the lessons learnt from applying this guidance. © 2013 Taylor & Francis Group, London, UK.


Li Z.,University of Cambridge | Soga K.,University of Cambridge | Wright P.,CH2M HILL | Wright P.,Tube Lines Ltd
Canadian Geotechnical Journal | Year: 2016

The behaviour of cast-iron cross passages in the London Underground was investigated using three-dimensional finite element models. Unlike the behaviour of a full tunnel ring, the structural integrity of a tunnel cross-passage opening relies on support from adjacent linings. In clayey soils, the opening may deform further as the soil stiffness changes from undrained to drained conditions. Degradation of the circumferential bolts and trackbed may also lead to further tunnel movement. A parametric study was conducted to examine the influence of soil stiffness and structural components (e.g., bolts and lintel) on the structural integrity of a tunnel opening. Results show that a lintel effectively transfers the load above the opening to the adjacent linings, and its distortion affects tunnel deformation significantly. If a lintel is not present, both bolts and friction between tunnel segments provide shear resistance to the lining deformation at the tunnel opening against soil loading. Results are compared with field observations made at a critical cross passage in one of the London Underground tunnels. The findings contributed to identifying the critical deformation mechanisms of cast-iron tunnel cross passages, which can be useful during inspection of such structures. © 2016, National Research Council of Canada. All rights reserved.


Li Z.,University of Cambridge | Soga K.,University of Cambridge | Wright P.,Halcrow Group Ltd. | Wright P.,Tube Lines Ltd
Tunnelling and Underground Space Technology | Year: 2015

The behaviour of cast-iron bolted tunnels in London underground railway network was investigated using the 3-D finite element (FE) method. A series of numerical simulations on a cast-iron segmental ring were conducted and its performance was compared against the analytical assessment used by London Underground Limited (LUL). Unlike the 2D plane model used in the LUL standard, the proposed FE model considered the 3D lining structural features (i.e. the geometry of the tunnel segment and the bolted joint) in a detailed manner. The behaviour of a cast-iron tunnel primarily goes through three stages: tunnel construction, soil loading and structural deterioration. At each stage, the influences on the tunnel behaviour such as external loading, soil-tunnel interaction were examined. Considering that, the proposed model thus resulted in more realistically structural performance in agreement with the field measurements. © 2015 Elsevier Ltd.


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).


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.


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.


Wright P.J.,Tube Lines Ltd
Proceedings of the Institution of Civil Engineers: Geotechnical Engineering | Year: 2013

The paper presents the results of a desk study on London Clay and a soil investigation carried out from inside London Underground deep tube tunnels, as part of the obligations of the Public-Private Partnership contract to assess the deep tube tunnels. The desk study considers the geological and drainage factors affecting the coefficient of earth pressure K0, and its relationship with depth below ground, and some evidence from tunnel circularity data is presented to support this. The resulting model is extended with considerations of how undrained strength varies with depth. A site investigation conducted from inside the tunnels is described, and the results are presented and discussed in the light of expectations from the desk study. Results for strength and stiffness testing are in general similar to those predicted. Of particular interest are the results from piezometers installed adjacent to the tunnels.


Grassie S.L.,RailMeasurement Ltd | Fletcher D.I.,University of Sheffield | Gallardo Hernandez E.A.,National Polytechnic Institute of Mexico | Summers P.,Tubelines Ltd
Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit | Year: 2012

In the mid-2000s, a new rail defect that was initially classified as a squat became increasingly common on London Underground's track. By 2006, there were about 600 of these and they had become the Underground's single most common rail defect. This defect occurred almost exclusively on lines carrying relatively new rolling stock. The work reported here was undertaken initially to characterize this defect, advise as to whether it was indeed a squat, and propose a hypothesis that explained its mechanism of formation. This paper includes observations and track measurements made in the field and initial results of a metallurgical analysis. The hypothesis for formation of the defects is presented, and both similarities and differences are discussed between these defects and the classical 'squat'. The defect on London Underground appears to be the same as that described by Marich and his colleagues in Australia and by Li and his colleagues in the Netherlands. It is evidently not a conventional rolling contact fatigue defect. In order to avoid confusion arising from simple misuse of an established term, it is proposed that these defects be given a different name, for which 'stud' is proposed. Evidence to date is that the 'stud' is a significantly more benign defect than the 'squat'. © 2011 Authors.

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