The only thing that I can see is maybe for easy trolley removal for maintenance. Other than that there would be no reason for it. ■

The inclined beam is far too heavy for the duty since the smaller beam is supporting the loads. In consideration of this deadweight imbalance I suggest the pin joint has been introduced only to accommodate deflections encountered during erection and then braced out after the machine was seen to be aligned. The proper way would be to leave a gap along the inclined beam so that the tripper could behave as a pin jointed frame with more substantial wheel contact. Since the bracing is relatively small it must be in tension and this implies that the lower beamS are lifted into hogging positions during alignment and simply left there.

In view of Putin's overtures to India and the parlous Russian economy perhaps it will be curried whale-meat on Leningrad menus this Christmas. ■

Originally Posted by d2vdt2

It could be that there are more than two axles. The pin joint allows all wheels (in particular, the driven wheels) to share load and make contact with the track under different loading scenarios.

Agreed,but as mentioned in the original thread the pin joint has been disabled by the angle bracing. ■

Hello,

I am not very clear about the issue but you are referring to some pin joint, etc. In this context, see if following information helps you to know about the reason:

For general traveling tripper, usually tripper chassis has cantilever portions beyond wheel span, one at forward end and another at rear end, as a single entity of structure.

Now, the rear end cantilever has less load compared to forward end cantilever. It has been observed that one can extend the rear end cantilever, by hinged tail supported by tie-rod and small vertical member (mast) at the rear end of chassis. Such arrangement is structurally economical. The extended rear zone of tripper reduces the unsupported belt length, at concave curvature. This means gradually rising more suitable tripper, with little increase in price.

In case the above information is out of context, then I suggest to discuss the issue with your structural engineer and he could be in a position to explain the reason for particular features in structure, in relation to structure twisting and load distribution within the chassis, etc., as a consequence of tripper travel on rail and rail alignment tolerances.

Regards,

Ishwar G. Mulani

Author of Book: Engineering Science And Application Design For Belt Conveyors (new print November, 2012)

Author of Book: Belt Feeder Design And Hopper Bin Silo

Advisor / Consultant for Bulk Material Handling System & Issues.

Pune, India.

Tel.: 0091 (0)20 25871916

Email: conveyor.ishwar.mulani@gmail.com

Website: www.conveyor.ishwarmulani.com ■

This tripper travels over bunkers and is therefore not so big. It was also the subject of design error. Why would anyone fit more than 2 axles on a bunker tripper? A pin joint was designed into the system and when the thing was nearly made the crew saw that the short assembly was going to tip over the belt at one end or t'other, probably both. So they built a continuous upper beam but rather than discard the pin joint they welded bracing over to eliminate the potential collapse. Examine the drawing history, if there is such a thing in that locale, and check if the As Built bears any resemblance to the Approved for Construction. Then let the signatories discuss it amongst themselves. Why? Because the upper beam is possibly still overloaded. You ought to be asking "Who approved either works?" ■

Except for the maintenance ease it does not seem to have any other reason OR this could be a site fit engineering ■

Originally Posted by Rajesh Mendiratta

Except for the maintenance ease it does not seem to have any other reason OR this could be a site fit engineering

Kindly, anybody, enlighten me on the maintenance advantages!

Obviously this was a site fitted bracing. The question is/was why? ■

This looks like something from the pages of Stan Walker....a UK manufacturer in the late 1970's early 80's who started with good intentions but left his detail designers, particularly sparkies, to destroy everything they could. I've watched in amazement as his commissioning crew ripped the cables and trunking out of a bucket wheel reclaimer because somebody overlooked the slew drive.

Structural shortcomings taken for granted: what are the chances of the long travel supply cables getting sheared by the wheel flange when the pathertically fragile rail plough comes adrift? Talk about nip point...! ■