70 kilograms per square millimetre over open grating & 500 kilograms per square metre if it can be swamped by retained spillage or maintenance loads. Those were British National Coal Board guidelines/requirements as far as I can remember. ■

Dear aech,

I will not be able to say the walkway load values as per British Standard. However, general information is as below. I presume you are referring to live loads.

The live load magnitude is subjective to the duty class of conveyor. In case of light duty conveyors, people had / have been designing conveyor gantry / gallery with a live load of approx. 300 kgf/m2 (3000 N/m2). However, for heavy class conveyors, people have been taking load up to 500 kgf/m2 (5000 N/m2). In case of light duty mobile machines, people tend to take somewhat lesser value of live load.

While deciding the live load, one also considers the weight that the maintenance people are likely to carry on such walkway. Suppose if you have got a 650 mm belt conveyor in that the idler weight will be very less and everything will be of smaller weight. However, if the conveyor is of say 1600 mm belt width, the belt, idler and everything will be heavy and load casually coming because of such items during maintenance etc. will be of higher order. In case of open gantry, engineers tend to take somewhat lesser live load say in the range of 2500 to 3500 N/m2.

If you have to abide by the statutory rules then the values will be accordingly. But possibly they might have also given a range.

Regards,

Ishwar G Mulani.

Author of Book : Engineering Science and Application Design for Belt Conveyors.

Author of Book : Belt Feeder Design and Hopper Bin Silo

Advisor / Consultant for Bulk Material Handling System & Issues.

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 25882916 ■