I am currently working on a project to evaluate existing lifting devices per BTH-1. One of the devices drawings (1954) lists the material as A284 Gr A. Does anyone know were I can find the tensile and yield strength?
Going back through references suggested I came up with the attached method. For the method the force in the pads / bolts uses the full moment of inertia which when I perform a check of the forces around the axis the resultant moment does not equal the initial moment. This is due to the local...
This is for a trolley frame on an overhead crane. I am being asked to provide calculations showing a frame is capable of withstanding the resisting moment due to equipment such as gearboxes and brakes. I am having trouble figuring out how obtain the forces / moments to apply to the frame. Does...
Per OSHA 1910.23(e)(1)
A standard railing shall consist of top rail, intermediate rail, and posts, and shall have a vertical height of 42 inches nominal from upper surface of top rail to floor, platform, runway, or ramp level.
My question is has OSHA ever defined "nominal" for a range when...
Thanks everyone with for your responses.
What I was able to find out after contacting our rail manufacturer was that by industry standard any gap greater then 3/16" under the rail to the top of the girder for a bridge crane is considered excessive and that no specification or standard addresses...
I have checked out AISE TR 13, AISC DG7, and Tips for Avoiding Crane Runway problems. I cannot find any thing that correlates to the distance between the bottom of the rail and the top of the girder, at the rail clips there is little to no gap but between the rail clips some locations there is a...
Yes we have rail clips at least every 36 inches but the girder has a camber in it and the rail is not perfect so there are gaps at various point between the two.
In CMAA 70 (2010) all I can find is in section 1.4.5 which is horizontal rail separation at joints not exceed 1/16", could you please direct me to which section in CMAA 70 refers to the gab between the bottom of the rail to the top of the girder? Thanks.
I am trying to find out if there is a specification or information on the maximum gap under the crane rail and the girder for an overhead top running bridge crane?
I am currently working on a retrofurb of a crane and the customer wants an equalizer bar assembly and the only place to place it without losing hook height is over the upper nest and using the equalizer sheave to reroute the ropes as shown in the attached drawing. Now the purpose of the...
They have 2 coils with a mechanical switch once the brake is energized initial draw is 4.6-5.9 amps but then switches to .09-.07 amps once repositioned which will be the state I am dealing with on loss of power.
I am currently working on a project were I have a primary and secondary brake and the secondary brake needs to have a 1-3 second time delay after the 1st break sets. For this application we need to use two electromechanical brakes and the brakes selected use a solenoid. My thought was to place a...
I am currently working on a project where I have to make a foot walk on a crane OSHA compliant, to meet the 48" rule from low obstruction the deck has to be lowered below the girder (W24x100) and outrigger (W16x26) by about 4-5 inches. The beams are 47 inches apart centerline to centerline and...
Those suggesting computer model, we do not have any such program and for the number of times we would need it would not be worth it. So that is kind of out.
IFRs: the angles does not pass the load calculation when run as a flagpole.
So I am searching for a method (other then computer based...
Yes the reason behind the size is per OSHA, we have used this size for our hand rails for years but our current customer is very particular and wants calculations backing up the size of the posts. The customer is adamant about the NAAMM nomograph is only for pipe hand rails and cannot be used to...
On a current project I am trying to use L2x2x3/8 as posts for a guard rail on a crane based on our stress limits the post fails under the full 200lbs OSHA requirement. My question is does the NAAMM Nomogragh also apply to angles as post or is there another way of determining the load applied to...
