Hi Tom,

I´ve seen some regulations about standard dimensions for walways and its acessories, but nothing about its acesses.

It is not always practical to provide acesses at regular intervals.

Greetings

Alexandre ■

You say the design shows the exits and then later say the designers have no reason for this. If you have long overland conveyors shouldn't they hug the ground to save on structural cost anyway? If you are talking about elevated conveyors in a plant then the HSE, Fire Fighting & Owner Standards & regulations will apply. With enclosed conveyors it was usual to aim for 50m spacing between exits but this was often waived in favour of a staircase integral to the GTU tower & short staircase near the tail or other convenient siting & leave the rest the sprinklers.

If you refer again to your Australian Standard AS2419: 1996 Ammendment, Clauses 4.3.1.2 & 4.3.1.3 might give you an indication of the situation. A firefighter might require access to an indoor hydrant in which case all points on the floor must be within reach of a 10m jet issuing from a 30m hose length. Frightening isn't it? Clause 4.3.1.5 will cheer you up even more.

AU$30k was the price for a reasonable stairway not so long ago. A ladder would be a lot cheaper. Don't forget to budget for illuminated exit signs & such if you intend to keep the authorities & workforce happy. You just have to consider the schedule impact if the HSE pick it up & force a messy redesign. ■

Ok, did miss something?

Which type of conveyor set up?, is it an overland conveyor or

underground, or on top of a storage storage bunker or a mill type of set up feeding processing machinery of some type?

Or is what you are referring to an elevated walkway along an elevated beltline with access and egress via exposed to the elements via exterior staircases to the elevated walkway?

Thats what it sounds like.

Here in the states access stairs are both at the head drive end and tail pulley ends and elevated walkways in between them with the walkways on one side of the belt structural members.

Typically a belt conveyor of any substantial length may have a cross over walkway that clears the top of the troughed belt with a full load of ore on the belt if that is what you mean to say.

lzaharis ■

We seem to be enjoyably entering a detail design excercise. The fire & HSE business will come down on you if you are in a plant or area which falls under the authority of a local fire chief. HSE will be concerned with paramedic stuff and stretcher access. It is 2008 and such issues are rightly important. Even if the conveyor is in a rural area the statutory mining regulations will still apply. After an event the Court will examine for due diligence etc. In Australia if you know of an event/risk anywhere in the world then you must account for it in your design. (If you have heard of belt fires in China then the risk assessment must assume that you will have a fire on one of your own fire retardent belts. If there are venomous snakes in the area then someone will get bitten.)

If your client is of a 'claim jumping' kind he will obviously be oblivious to modern stringency and refuse to pay for the accesses. You need to cover yourslef in writing and you are professionally obliged to advise a client only once. That done, anything reasonable goes.

Although stiles might allow you to double the pitch of exits there will be a headroom issue with enclosed gantries which might prove just as expensive. ■

It would help a lot if we knew what he is doing rather than us throwing darts at a dart board in a totally blacked out room for him.

lzaharis ■

Well said, very well said. ■

It would also be helpful to know what country the design will be used - it will vary greatly between countries. ■

Whoops- I actually ment to use "Nerf" darts I do not want to be accused of causing a lost time injury and being subjected to the usual "spanish inquisition" that my former employer uses in workmens compensation cases/claims.

lzaharis ■