Pull wires are a legal safety requirement in civilised countries & most others as well. Proposing a hedge to guard a pulley is rather like asking us if we would consider visiting you in prison.

It seems that you anticipate public intrusion & vandalism along your conveyor line. Your only solution is to enclose the lot. Normal IBR cladding is inadequate. The entire line must be encased which may restrict your aspired mobility. I cannot fathom out the drawbacks of pull wires; vandals can syphon off the diesel while the conveyor is still running.

For start up you need 4 people otherwise the line will run empty for the length of time it takes 1 man to walk 1.5 kms. Add to that the engine start up time & disabling the tail cut outs; is there 1 on the first unit? You seem to have introduced longcuts to the previously simple task of conveyor design. ■

I second johns excellent comments,

In your case you might consider a capsule pipeline for you project. it has the ability to be easily moved by utilising "Victaulic clamps" to connect the pipeline sections and does not require any of the items required for a belt conveyor.

Please investigate www.capsu.org to see an existing system in use in japan the system in use replaced a rail line from a quarry to a cement plant.

Also investigate www.pneutrans.net the pnuetrans site has a page where you can type in all your requirements and mr. Weaver will give you a free quote for a capsule pipeline system.

Disclaimer:

I do not represent pnuetrans or any other organisations. ■

There isn't an alternative to a pull wire. It is a legal H&S necessity. Your train of thought is highly dangerous.

A jeep completing 2km in 5 minutes with 3 stops to reset a cut out & then start up a genset is quite some jeep. In the civilised world it is customary to give 3 minutes start up warning for a conveying operation. In most parts it is written into the Mines & Quarries Acts.

Who writes the Specifications; John Wayne? ■

It is a very realistic option simply due to energy costs an labor costs. You have the ability to run as many capsule trains as you wish at speeds up to twenty five miles per hour and higher alll with air pressure and it can move millions of tons per year.

A capsule pipeline system will cost much less to operate and maintain and by using a synchronous motor you will be able to generate electricity while operating in reverse. capsule trains

can consist of up to five cars in each train which move from the loading point to the unloading point and back.

The system can be set up as a single pipeline or in in a loop which allows one to run continously or with a paralell pipeline set up with two pipes next to each other where the capsule trains are unloaded or loaded and slid over to the other pipeline and pushed back into the pipe for delivery to the other end for either loading or unloading.

When you look at the pnuetrans site you will see a cost comparison of various methods of haulage and the capsule pipeline will have operating costs of two and one half cents per ton mile.

How many tons per year are are you planning on moving from point A to B?

minimum tonnage is 100000 tons per year and the minimum distance is one mile.

What are the desired operating hours?

a capsule pipeline operates with in a sealed pipeline and is unaffected by weather and it may be mounted on the surface of the ground or buried if one wished out of view or tampering from vandals.

In the pnuetrans site a link leads to a questionaire that you can fill out and Mr. Weaver will send you a no obligation free quote for one of his systems and its requirements.

www.pnuetrans.net

If you have a very small labor force the capsule pipeline lends itself well to it as very little labor is needed due to its simplicty and few moving parts.

Using Victaulic clamps and grooved pipe lends itelf well to the capsule pipeline system for mobility as it can be easily moved if it is installed on the surface just like railroad track panels.

No drive units, no idlers, belt stands, transfer points, tail pulleys, conveyor belt, belt splices no stopping production to change bad idlers, repair splices, no greasing idlers, no worries about belt spills, no chute plugging, no shoveling and it is fully automatic just like a bank tellers pnuematic tube.

Overland conveyors are not designed to be moved readily and you will have problems simply because everything must line up all the time every time ■

Hi Johan,

I am coming in a little late but it seems to me there are alternatives that will insure safe operation. In both underground coal mines and many overburden operations the problem you are facing is a common problem. While the absolutely preferable option is a lanyard system you can effectively isolate a conveyor by installing a local isolation device every say 30 metres. If this system is used you need to have a safe management plan in place that includes guarding along the conveyor that can only be removed when it is locally isolated. This is a matter of working through this option with your electrical people to ensure that the local isolation is a secure system and it does mean that you have restrictions as to access while it is operating. Such systems are used in "civilised" countries and are very effective and definitely a lot less expensive that enclosures etc.

All the best

Col Benjamin

Gulf Conveyor Systems ■

Hi,

Sorry for the delay in reply but I have been away. I do not know companies to refer you to outside of Australia but you need to talk to a company who supplies electric componetry and in particular isolation devices for electrical motors. Some of the companies who supply lanyard systems are also familiar with local isolation devices. They operate with usually with a switch and a locking device where you apply your clasp lock. If you want me to refer you to companies that can help then email me directly colin.benjamin@gcsm.com.au. In respect to what you also need to do, you need to guard the conveyor and have a management plan that ensures only authorised people access the area. If there is the chance wildlife or unauthorised people could trespass the area then you need to have some form of lockable, demountable fencing. In the underground coal industry restraining unauthorised access is easier obviously than on the surface and in such circumstances the guarding usually only covers take up areas, drive and serious nip points with the remainder of the conveyor has lighter easy to handle guarding. I believe it is also important that any inspections done while the conveyor is operating should be done by 2 people. If you want to fully protect yourself get what you propose independently audited and having taken all these precautions you are reasonably covered providing those that work for you are aware and trained to follow the correct procedures. All this may sound a lot but we have laws in Australia about "Duty of Care" and in such circumstances if you cannot follow normal industry practice then you must be seen to have followed a rigorous process to cover yourself in the event of an accident

All the best

Col Benjamin

Gulf Conveyor Systems ■

OK so somebody gets dragged along 30 metres of scrub & then quickly switches off the conveyor with his remaining free arm before getting dragged along to the next isolating station. Then you fit lockable demountable fencing to a line of what are supposed to be moveable conveyors. All in place of a bit of string that has performed to the satisfaction of statutory bodies, manufacturers, miners & quarrymen all over the planet for more than my lifetime. Why? ■

I agree with you completely john.

leon ■

John,

This is unduly alarmist and not rational. Unfortunately I visit many sites where the lanyards are incorrectly installed and would not work, where they are too slack and could not be operated. Saftey is paramount we all agree but if you have a belt system that is regularly shifted and moved it is more likely that the lanyard system will be at times be inoperable. This requires a different approach without trying to encapsulate the conveyor where a fire or other event may be created that also has safety consequences. The key issue with lanyards is stopping a belt when someone has been trapped by his clothes or hand by an idler or at some other nip point. Obviously there are other possible safety issues as well but this is the main issue. Through guarding and a proper management plan there are effective and safe options and these have been used with no more risk than systems with lanyards. It is important to note that most lanyards systems do not isolate the power source and therefore are not regarded as isolation devices, the system I have seen operating does so it is intrinsically safer as far as belt access is concerned. How many times do lanyards get used to stop a belt so an idler gets changed out?

Col Benjamin ■

Dear Mr. Brands,

The belt conveyors are constructed in three versions :

- Permanently installed staionary conveyors

- Relocatable conveyors

- Shiftable conveyors

It seems you would be implementing project for relocatable conveyor. The main point in design and construction of such conveyor is to create various assemblies suiting to the transport vehicle, with least amount of dismantling and reassembling. Also, wherever possible such assemblies should be in modular version.

As for the pull cord switches, it allows the emergency stoppage of conveyor by anybody who is near the conveyor and who sees technical distress or other kind of distress. This becomes possible because the pull cord is running along the conveyor and instantly accessible. It is like a pull chain in a train. The only alternative could be to provide number of stoppage push buttons, but this will be more cumbersome with so many wires and so on. In strict sense there is no substitute to pull cord emergency stoppage. Also, the emergency pulling chain in train has created a permanent impression in the public mind in a very extensive manner about the function of such item and the person reaction would come instantly for right action.

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 ■