Spiders on Motorways - safer / easier grass cutting for operators

The IDL2 Spider remote-controlled mower from Dvorak Slope Mowers in the Czech Republic is a (www.spider-cz.com) 400-lb, low profile 4WD mower is powered by a 17-hp / 500 cc Twin V 4 stroke Kawasaki petrol engine and cuts a 31.5-in. swath on slopes up to 40 degrees, typically the job of manual weed whackers. Speed is variable up to 7 km/hr (forward or reverse) and is controlled by a hydraulic pump that drives four separate hydraulic motors, one per wheel.

The operator has control of , stop/start, steering, speed, blade control and height.

The UK Highways Agency is testing the device on the M4 near Heathrow as forthcoming changes in Health and Safety legislation will affect the use of strimmers or weed whackers and this allows the user to operate the device from a safe position, reduces sound (it is rated at max. 100dB(A) LWA) exposure and eliminates vibration to the operator as well as eliminating physical dangers of riding on the mower on rough ground.

Impending changes to exposure of employees to vibration will take effect from July 2007 and are explained in an HSE leaflet (pdf alert). Vibration is calibrated as exposure action value (EAV) For hand-arm vibration the EAV is a daily exposure of 2.5 metres/second squared (m/s2 A (8)) . Strimmers typically are rated at 4.00 m/s2 .The exposure limit value (ELV) is the maximum amount of vibration an employee may be exposed to on any single day. For hand-arm vibration the ELV is a daily exposure of 5 m/s2 A(8).

Francis Cluett, area manager, for the Highways Agency said:

"Keeping the men and women who maintain our roads safe is a high priority for the Highways Agency. New technology, like the Spider, allows us to maintain the verges while workers stay at a safe distance from the traffic."

Dr Ken Young at the Warwick Manufacturing Group of Warwick University is leading a team developing a computer controlled robotic version of the4 Spider , which would ultimately enable teams of robots to cut playing fields or even golf greens.

The Spider is sold by Jacobsen (Division of Texron Inc.) in the US and Ransomes Jacobsen in the UK.