SCRIM® celebrates 50th anniversary
To celebrate the 50th anniversary of the SCRIM® (Sideway-force Coefficient Routine Investigation Machine), we share a SCRIM fact each week during 2017.
Fact #1: W.D.M. Limited celebrate the 50th anniversary of SCRIM in 2017 – it was the machine that resulted in the company first becoming involved in the highway asset management sector.
Fact #2: SCRIM is an acronym for Sideway-force Coefficient Routine Investigation Machine.
Fact #3: The first SCRIM was built in 1967 for TRRL (Transport Road Research Laboratory).
Fact #4: SCRIM measures the wet road skid resistance to ensure the surface meets regulatory levels and is safe for vehicles to use.
Fact #5: SCRIM measures the microtexture (roughness) of the surface chippings by lowering a freely rotating wheel on to the road at an angle of 20% to the direction of travel, under a fixed load. A jet of water is sprayed on to the surface immediately in front of the wheel, which is in continuous contact with the road. The force exerted on the wheel is measured by a load cell.
Fact #6: The SCRIM measurement tyre is a slick – it has no tread to influence the skid resistance of the road surface and is specially made for WDM® to fine tolerances to ensure consistency.
Fact #7: SCRIM operates around the world and there are machines in 18 countries.
Fact #8: WDM® has built more than 80 SCRIMs over the last five decades.
Fact #9: Measurement wheels are normally mounted on the nearside of the vehicle, but some have measurement wheels on both sides, particularly those manufactured for overseas clients.
Fact #10: WDM® operates a fleet of SCRIMs in the UK, surveying the motorway network and main trunk roads.
Fact #11: The water tank on a SCRIM ranges from 1,900 to 12,000 litres.
Fact #12: SCRIM uses an inertial GPS system to ensure total accuracy of its data.
Fact #13: SCRIM has dynamic vertical load measurement of the test wheel.
Fact #14: The dynamic water flow control means SCRIM promotes economic water use by reducing flow at slower speeds, whilst maintaining water film thickness during surveys.
Fact #15: WDM® is the sole licensed manufacturer worldwide of SCRIM, which is manufactured under license to the UK Transport Research Laboratory (TRL) in full compliance with the current British Standards BS 7941-1:2006.
Fact #16: WDM® founder Leslie Gardiner worked with the Road Research Laboratory to develop SCRIM after he was asked by the Ministry of Transport to adapt a lorry to test the safety of road surfaces.
Fact #17: The WDM® SCRIM is a completely self-contained system consisting of a vehicle chassis fitted with a large water tank, one or two measuring wheel assemblies and data recording electronics.
Fact #18: SCRIM is also fitted with a forward-facing video to record the survey route, capturing one frame every 5m, each of which is logged with its GPS location.
Fact #19: If the longitudinal profile option is selected, SCRIM can calculate and record longitudinal roughness, expressed as IRI and Variance (3, 10 and 30m wavelengths) simultaneously.
Fact #20: The introduction of regular SCRIM surveys, together with a skid policy based on the current standards, offers a very cost effective option for local authorities to achieve and maintain reductions in their road casualty rates.