Welcome To Our New Website                       6th June 2005

We hope you like the new design and are finding the changes an improvement over our old one! We have tried to make it more ‘user friendly’ and hopefully it’s now far easier to find the information that you’re looking for. We will in the future be using this page to update you on what is happening within the company, but also on any issues that come up within the industry that we think will be of interest.

Firstly we’d like to tell you about two significant new appointments within the company. At our Bath office, Matthew Anderson has been promoted to the position of Managing Director – Operations Division. He is now responsible for all activities relating to our specialist services which encompass all aspects of structural monitoring and stress analysis, including operational activities at both Cowes and Aberdeen. At our Cowes office, John Astrup has been appointed Managing Director – Products Division, and has the task of ensuring that the factory runs smoothly and that all orders are correct and delivered on time. We hope you will join us in wishing them both every success in their new roles.

Strainstall Introduce Three New ProductsDGPS Based DockAlert
Vessel approach systems that use traditional lasers are only able to monitor an approaching vessel when it is within the laser beams, which are perpendicular to the jetty. In order to offer a speed of approach package suitable for a number of applications, Strainstall have developed a DockAlert system that uses DGPS (Differential Global Positioning System), which provides centimetre accuracy.  This also expands the package by providing a small vessel traffic management capability, as it is able to monitor the approach of the vessel from a much greater distance from the jetty and from any direction - in effect from when the pilot boards the vessel.
 
The basic system requires 2 DGPS sensors to be positioned onboard the vessel, a reference station on the jetty and a base station with display for the control room. A chart of the area is shown on the base station display PC and the vessel is shown with its speed and direction. A palmtop can also be provided for the pilot to carry on board the vessel that provides him with a continuous distance and speed of approach during berthing.This system can also be used with vessels that would present a curved surface to a laser, i.e. a Ro-Ro vessel bow on approach to the linkspan. DockAlert can provide a valuable aid to docking safety, and is equally suitable for oil/gas product carriers, Ro-Ro vessels and high speed ferries.

For further information contact marine@strainstall.com  



SloshAlert
Our new SloshAlert system measures the load on the insulation system of a LNG carrier caused by the sloshing motion of the liquid in the tank. It has been designed to meet the new classification society requirements, including the recent DNV Part 6, Chapter 11 (Jan 2005). Cargo sloshing in membrane tanks has been a topic of special focus for DNV, as sloshing in partially filled tanks induces both fatigue and high loads upon the containment system, the hull structure and the pump tower in the tank. SloshAlert utilises sensors to monitor these stresses and provides the Master with instant access to the data, as well as a permanent record for post voyage or long-term analysis.The large number of sensors and high sampling rates required to meet the rules has been accomplished by using the latest fibre optic TDM (Time Domain Multiplexed) technology. The use of fibre optic sensors is particularly suited to this application, as they allow for the positioning of sensors in hazardous areas where extreme temperature variations may occur.For further information contact marine@strainstall.com  



Stressalert FO
StressAlert FO is a variant of the established StressAlert Hull Stress Monitoring system, but ulitises fibre optic strain sensors in place of the conventional extensometers and strain gauges. Fibre optic sensors provide a number of advantages, including freedom from electrical interference, intrinsic safety and multi-channel operation. The system is suitable for a wide range of ships, including FPSO’s, oil and LNG tankers, bulk carriers and container ships. It provides essential monitoring of structural integrity throughout the life of a vessel and enables the master to pilot his vessel to the maximum safe efficiency.StressAlert FO is built to meet requirements for electrical apparatus operating in hazardous areas and is approved by marine classification societies. For further information contact marine@strainstall.com  

 

Recent ProjectsFlood Warning System for Rail Bridge
We have recently completed the installation of a novel flood monitoring and warning system. The particular bridge is over a river that frequently experiences flash-flooding. The flood events last for a few hours, and the flood level is often above the soffit level of the bridge.
 
The monitoring system incorporates water level sensors, displacement sensors (to measure whether the bridge deck moves on its supports) and cameras. The system measures the water level and predicts the time the 'danger' level will be reached. It is powered by renewable sources. The information is sent automatically in real time from the remote site to a control desk, where an operator can decide whether the bridge needs to be closed to traffic.  The operator also has access to real-time images of the flood condition via the cameras.


Dynamic Monitoring of Railway Points
Strainstall's Rail Points Load Pins are widely used in heavy rail and metro applications. These are normally used for condition monitoring, and provide information concerning the forces needed to operate the points, giving a pre-warning of a maintenance problem.

One of the metro infrastructure companies has appointed us to carry out a programme of dynamic tests using the same points pins, but with dynamic data acquisition equipment. This will enable an assessment of the potentially damaging effects that passing trains have on the points machinery i.e. linkages and motors. The first phase has been successfully completed at a training compound and the tests at a 'real' site are to take place within the next few months.


Parapet Test Slab
We were appointed to assist with the instrumentation and testing of a parapet test slab. The test slab was designed and constructed to have details representative of a large number of bridges, that are theoretically unable to support the loads generated when a vehicle hits the parapet.
 
We have installed some 124 strain gauges on numerous reinforcing bars, prior to their assembly and the concrete pour. We then provided a static monitoring system and incorporated a load cell within the jacking assembly. During the test programmes, we monitored the applied loads and the strain effects on the reinforcing bars. It is hoped that the trial will give some confidence that there is hidden strength in this type of bridge deck, thereby helping to prevent the expense and disruption associated with strengthening of a large number of bridges.


Load Measuring Pins
Strainstall are to supply 24 large load measuring pins for the mooring system of a new offshore platform. Built at Jurong in Singapore, the structure is to be delivered in early 2006 to the Gulf of Mexico for completion, where it will be tied into six fields within a 30 mile radius. In a water depth of 8000 feet, it will be the deepest semi-submersible floating offshore installation in the world. The platform will be moored by 12 polyester mooring lines with a breaking load of 1770 tonnes each, with the load measuring pins installed in the chain stoppers that secure the lines to the platform. Each chain stopper will have a pair of load measuring pins, one left handed and one right handed.

These load measuring pins will be used to provide continuous measurement of the loads on the lines, with data fed directly to a centralised computer system to give real-time information and warning of any overloads.


Sail Load Measurement for Orange II
Orange II is the 110ft long sailing catamaran that recently set a new round the world record in 50 days, 16 hours, 20 minutes and 4 seconds, achieving an average speed of 22.2 knots. To reach the speeds necessary to break the previous record Orange II needed an extremely powerful set of sails, as the strains they would be subjected to in the varying sea conditions and wind strengths would be measured in tonnes. To enable them to monitor these stresses our load pins were incorporated into the winches. This gave the crew vital information on when maximum strains had been reached, allowing them to alter the configuration of the rigging to avoid damaging the sails and jeopardising their record attempt. 



Tendon Tension Monitoring System for West Africa
We recently completed the commissioning of a Tendon Tension Monitoring System (TTMS) on a new Tension Leg Platform (TLP), deployed in the waters off West Africa. This was the second system supplied to the customer, which comprised of 24 dual bridged compression load cells rated at 2,500Kips, signal conditioning, operators display station with dual redundant PC’s running Strainstall’s TTMS software and I/Os to a number of other systems.

The system monitors, calculates and displays the tensions and bending in each tendon and the data is used to assist in controlling the ballast condition. The load cells were designed and manufactured by Strainstall for a 25-year life for operation at over 40m subsea. We are currently completing the manufacture of two more TTMS systems for TLP’s, also to be deployed in the waters off West Africa.


Extended Hull Stress Monitoring System
We have recently supplied expended versions of our StressAlert II system for a number of new build ships and stretched vessels to meet customer and classification society requirements. Two systems were installed on new build LNG carriers that meet the requirements of DNV HMon2 Notation requirements. These included the integration of wave condition monitoring, monitoring of the LNG tank loads imposed on the skirts, and additional long-base strain gauges. A further system has also been supplied for a joint project on a new generation of container vessel – approximately 9,500teu. In addition to the basic system, wave condition monitoring, structural monitoring of the hull and 6DoF motion sensors were added, with enhanced software providing raw (10Hz to 10KHz sampling rates) and processed data for analysis by both the owner and classification society. A system is also being installed in a car carrier to provide structural data on the hull to assist in future designs.


BerthManager Supplied to LNG Receiving Terminal
Our BerthManager system has been supplied to a new LNG receiving terminal being constructed in the Mediterranean. The system included our MoorAlert system for monitoring tensions in the mooring lines, and our DockAlert system for monitoring speed and distance of the vessel during approach to the jetty and drift-off one the vessel was moored. Also included was an environmental subsystem to monitor wind speed and direction, humidity, temperature, air pressure and solar radiation, and a pager system to provide both the pilot and jetty personnel with data.

The MoorAlert system comprised of Eex’sm’ approved load measuring pins for installation in the mooring quick release hooks and network interface units for mounting on each hook unit. The DockAlert system comprised laser sensors mounted on the jetty to measure speed, distance and drift-off of the vessel, with 2 large digit displays to provide indication to the pilot and vessel crew at distance of up to 250m. The BerthManager customised software provides the operator with real-time data on the vessel during approach. 

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