Strainstall - Measurement and Monitoring Solutions for Track, Switches, Structures and Rolling Stock

Strainstall systems monitor a complex array of parameters in the dynamic and often critical functions of rail tracks, bridges, traffic, vehicles and components. Working closely with the rail industry has provided Strainstall the opportunity to develop a number of specialist systems to help safeguard the rail infrastructure. These include the Points Pin points and switch monitor, TrackAlert for wheel impact load detection and systems for measuring in-situ stress, load testing and assessing structural health of structures and vehicles.

Strainstall have a wide experience of on-site structural testing. Through the use of appropriate instrumentation and sensors, Strainstall regularly test bridges, track and rolling stock and carry out analyses to determine structural behaviour.

RAILWAY TRACK POINTS OR SWITCH MONITORING

Strainstall holds the patent for the widely used 'Points Pin'. This force-measuring pin replaces a component within railway points to monitor the force required to operate. The remotely monitored information provides data for an enhanced preventative maintenance programme or even impending failure.

WHEEL IMPACT LOAD DETECTION

Analysis and train characterisation is provided by TrackAlert, our specialist system for monitoring rail traffic. The system uses existing rail bridges as dynamic weighbridges. A variation uses straingauges installed on the rails. Each time a train crosses the bridge, the system records data and immediately determines:

• Train speed, direction
• Train type, formation
• Bogie weights
• Overloads
• Wheel impacts

The system can be integrated with other available information, so that train and vehicle IDs are allocated to vehicle defect warnings. Warnings and information on potentially track-damaging occurrences are provided in real-time.

BRIDGE STRIKE DETECTION

Either as an enhancement to TrackAlert or as a stand-alone system, impacts from overheight road vehicles can be monitored.

Alarm messages are sent immediately which identify the part of the bridge that has been affected and how severe the impact has been. This information is backed up with a camera system.

BRIDGE LOAD TESTING

Strainstall has carried out work on hundreds of bridge structures, ranging in scale from Forth and Tay Bridges, Royal Albert Bridge and Newcastle High Level Bridge to three metro span underbridges. Working mainly with consultants and bridge owners, our comprehensive service not only deals with instrumentation and monitoring, but provides access to the information that is really needed about a particular structure.

We also provide instrumentation equipment for hire to contractors, particularly for use during repair or strengthening operations. This can include displacement and strain measurement equipment. Strainstall is able to assist in devising a suitable test or monitoring regime for problem structures. The information that can be delivered from our tests or monitoring systems includes comprehensive load test data, in situ dead load stresses or loads and ongoing structural health.

IN SITU DEAD LOAD STRESS DETERMINATION

Before the carrying capacity of a bridge can be properly assessed, the dead load stress conditions need to be known. This can be particularly important for post-tensioned concrete bridges. Strainstall have devised a number of techniques for the measurement of in-situ dead load stresses.

BRIDGE MONITORING SYSTEMS

Strainstall design, assemble, programme, install and operate monitoring systems of varying complexity. These range from simple, battery powered static logging systems to fully automated structural health monitoring systems. The parameters measured can include strain, displacement, acceleration, vibration, pressure, temperature and wind speed / direction.

BRIDGE STRUCTURAL HEALTH MONITORING

Many new, complex structures are fitted with structural health monitoring systems. These are designed into the bridge and provide a means for engineers to monitor the performance of key parameters under real environmental and traffic conditions. For a long span suspension bridge the measurements might include deck profile, cable load, hanger vibration, deck vibration, joint displacement and strain.

VEHICLE AND ROLLING STOCK MONITORING

Strainstall regularly install strain gauges and other sensors on rolling stock components, then carry out dynamic monitoring. The information obtained can be used in fatigue analyses. Permanent and temporary monitoring systems have been developed for measurement of ride characteristics, vibration and wheel / track interaction effects. These have been provided for major train manufacturers for use in the UK and worldwide.

INSTRUMENTATION

Strainstall offer rail operators and infrastructure maintainers a comprehensive range of site services and products which include strain gauge and sensor installation, dynamic testing and stress analysis of vehicles and components.