Bar Rail V ASCE T-Rail 1

[QA_Manager]

thread507-448084

Great previous conversation on this topic, a few follow up questions for Bar Rail v. ASCE T-Rail:

If Bar Rail is lighter, softer, and prone to chipping at butt joints, would an ASCE T-Rail be a better choice for ISO-8 cleanroom application?

A Bar Rail is welded, it doesn't allow for future adjustment, could be an issue as things 'settle' or otherwise get knocked out of alignment. Again, wouldn't the ASCE T-Rail with j-bolts be a better choice for alignment, maintenance, replacement, repair?

 

[SJBombero]

Chips flaking off the top rail is unavoidable. For cleanroom applications solutions are to provide upturned channels under the rails to capture flakes and magnets near the rail head.

ASCE rail is a better choice if future adjustment and repair are concerns.

 

[FLCraneBuilder]

-We have not see a chipping occurrence in the 200,000 plus feet of this product we have installed.
-the shop & field splices are installed with very tight gaps. larger gaps at rail ends will exacerbate the potential. same for asce.
-bare in mind that bar rails usually have much wider head widths. example - we use 1.5" wide bar in place of 30# asce (1.06" head). the bar has 30% wider head width.
-note also we buy 40' & 50 ft lengths of the bar - reducing the number of splices
- Ref the flaking - we shot blast the beam & bar assembly after welding - which reduces the flaking. the mill scale is for the most part removed
--- We would NEVER use this product on on high duty cycle crane. But it is suitable for light & moderate duty cycles
--- rail replacement is not a reasonable concern on a moderate duty cycle crane. it just never happens.
--- reference adjust ability, - if the runway beams are on haunches - insure that there are lateral slots at the runway beam to haunch connections. if runway is on columns, one can easily cut the tie backs loose & tilt the column a bit as needed. We've seen settlement problems on 30 + year old facilities. - but it usually in an isolated instance. - We have seen occasions where a forklift or a truck hits a column. but this is far beyond the system design criteria.