MOT test lanes come in various shapes and sizes, which all change according to the dimensions of the garage and the class of vehicle/s the Vehicle Testing Station (VTS) intends to test. The Vehicle and Operator Services Agency (VOSA) provides recommended layouts and test lane specifications for all classes of vehicle, in a document entitled "requirements for authorisation", which can be downloaded from: www.businesslink.gov.uk
However, please note that the specifications provided are the minimum test lane requirements for each class of vehicle. Meeting these minimum requirements will enable you to test most of the vehicles on the road in that class, but will not guaranty that you can physically test all of them. So be careful, if you intend to test a fleet of very large class-VII vans for example, it's worth checking that they fit into the test bay. Buying a class VII test bay does not mean that it will be able to test all class VII vehicles; it means that it meets the VOSA Class VII minimum requirements, so always check with your supplier who will be most likely be able to modify a standard lane to meet your requirements.
What type of lane?
Class IV and VII vehicles can be tested using a "standard test lane", a "one person test lane" (OPTL) or an "automated test lane" (ATL) all other classes can only be tested using a "standard test lane", so what's the difference? Well apart from the fact that a standard test lane requires a second person to act as an assistant, the only other difference is the level of equipment needed, for example a "standard test lane consists:
- An inspection lift or pit
- Jacking beam
- Roller or plate brake tester
- Headlamp beam setter
- Exhaust gas analyser
- Diesel smoke meter
A "One Person Test lane" requires the same as above, plus 3 additional pieces of equipment, which are:
- Steering and wheel play detectors
- Brake-pedal application device
- Light inspection mirrors or colour CCTV system
The additional equipment basically removes the need for an assistant.
An "automated test lane" comprises of all for mentioned equipment, but also calls for the brake tester to be fully automated. Using a fully automated brake tester speeds up the test by checking both wheels of the same axle at the same time, guides the examiner through the test and keeps a data base of vehicles tested. Running both roller sets together greatly shortens the time taken to conduct a test. However, using an automated roller brake tester for the first time does take some getting used to. One of the biggest problem areas is that of the operator applying the brake too quickly, which can cause the vehicle to climb out of the rollers, thus aborting the test.
With both wheels rotating there's nothing to anchor the vehicle in the rollers, so the brake must be applied slowly, once the operator has learnt this the test becomes very quick.
If you are operating as a standard test lane, to become a OPTL or an ATL you must reapply to VOSA.
All equipment used for tests must meet VOSA's specifications and all apart from the lift/pit and jacking beam must be fully VOSA approved, a list of approved equipment can also be found on: www.businesslink.gov.uk or on www.gea.co.uk
Apart from the major equipment, there's also a requirement for the following miscellaneous equipment:
- A tyre tread depth gauge selected from VOSA's latest list of acceptable equipment,
- Corrosion assessment tool,
- Suitable pinch bars,
- Steel tape measure,
- Wheel chocks for the class of vehicle to be tested
- A hand held low voltage inspection lamp.
- Adjustable captive bearing based turning plates
- A calibrated decelerometer from VOSA's latest List of Acceptable Equipment
Calibration and maintenance:
All testing equipment must be kept in good working order. Measuring apparatus must be calibrated in accordance with VOSA's requirements. If an Item of mandatory test equipment is not re-calibrated by its due date then testing which uses that item will be prevented until the item is re-calibrated. Maintenance contracts and calibration certificates are inspected regularly by VOSA.
According to VOSA's website, incorrect headlamp aim is the largest MOT failure item, with around 21% of heavy goods vehicles (HGV's) failing on headlamp aim every year; around 13% of passenger service vehicles (PSV's); and, 16% of cars.
So checking that VTSs are measuring and setting the headlamp aim correctly is becoming an important issue, here are the basic rules:
For a vehicle with headlamps positioned at a height of 850mm or lower to pass an MOT, the beam image "cut-off line" of both lamps should be between the two red lines of the equipment's screen; these are set at 0.5% to 2% inclination.
A vehicle with headlamps higher than 850mm should show the "cut-off line" between the equipment's blue lines, which are at 1.25% and 2.75%
On all headlamps the beam image "break point" should be to the left of the equipment's 0% vertical line and to the right of the 2% vertical line and the beam image "kick-up" must be on the nearside. A guide to correct headlamp aim can be found on www.gea.co.uk