Transportation of piperack modules
Transportation of piperack modules
(OP)
I have client specs that call for acceleration forces for transporting piperack modules to be 0.3g longitudinally and laterally and 1.5g vertically.
We have two transport options, Scheuerle (continuous low level loader) and dolly (independent front and rear axles, tied through the structural system being transported).
Unfortunately, the spec does not tell you how to do the analysis.
On the dolly system, I have engineers calculating the extreme longitudinal force, statically, on 30T (metric)load being 9T horizontally. This seems overly optimistic.
I believe the 0.3g is the variation during transportation. The problem must be accelerating and decelerating conditions and the weight should be thrown longitudinally, meaning the design force should be (1.0 + 0.3)g giving 39T.
On the scheuerle system it is not critical as the module is tied down everywhere and the transport base provides the stiffness for transportation.
Any suggestions out there ?
We have two transport options, Scheuerle (continuous low level loader) and dolly (independent front and rear axles, tied through the structural system being transported).
Unfortunately, the spec does not tell you how to do the analysis.
On the dolly system, I have engineers calculating the extreme longitudinal force, statically, on 30T (metric)load being 9T horizontally. This seems overly optimistic.
I believe the 0.3g is the variation during transportation. The problem must be accelerating and decelerating conditions and the weight should be thrown longitudinally, meaning the design force should be (1.0 + 0.3)g giving 39T.
On the scheuerle system it is not critical as the module is tied down everywhere and the transport base provides the stiffness for transportation.
Any suggestions out there ?






RE: Transportation of piperack modules
RE: Transportation of piperack modules
I have transported tall vessels on saddles, using dollies, but 36 m length piperacks of statically indeterminate stiffness?
Should 0.3g be the applied force in a single bracing or assumed distributed throughout. At least an estimate of stiffness of the system connecting the front to the rear wheels is required. The weight of the rear wheel system must also be included too.
RE: Transportation of piperack modules
RE: Transportation of piperack modules
This module on four columns is directly connecting the front to the rear wheels.
RE: Transportation of piperack modules
RE: Transportation of piperack modules
Client specs do not generally tell you how to do the analysis. The engineer designing the steel module should find proper design specs if the design company has no design guideline. Longitudinal force of “(1.0 + 0.3)g giving 39T” seems overkill. 0.25g is the force we use as the horizontal force due to braking or acceleration (in longitudinal and transverse directions, but they don’t happen concurrently, they are combined to 1.5g gravity load separately). Sometimes, most critical forces occur in structural members during transportation.
In analysis of transportation (On the dolly system), the front (and rear) columns may need to be designed to take the whole longitudinal force.
RE: Transportation of piperack modules
RE: Transportation of piperack modules
RE: Transportation of piperack modules
If your concern is for possible different response of the system (during braking or deceleration) with different natural frequency of the module (because of different stiffnesses), that is a good point. But the general design has not gone that far from my knowledge.