Load Combination - Cargo Tank

[VPbris]

Hi,

I'm studying ASME XII which is very similar in many aspects to ASME VIII-1. During my studies I came up with some questions hope you could provide me some help. There is a picture of the load combinations attached from (1-1.4).


1st. I'll treat the vessel as a beam, so in order to account for the heads (spherical in my case) I reckon I should consider some extra length on the cylindrical portion, any guidance on how much?

2nd. On Load Case A, I'm not really sure what W_h and W_w, stand for, I guess they stand for the weight of kingpin/rubberplate and of the wheels suspensions respectively, can someone confirm that?

3rd. Still on Load Case A, I determine the reactions on the supports, and then calculate the shear and bending moment diagram of the "beam" so that I can determine the bending and shear stresses. In order to combine with stresses due to pressure I can just perform a vector sum, as I'm considering a linear approach. Is that line of thought correct?

4th. Now on Load Case B. There is a paragraph before the image that reads the following

(2) Dynamic Load Condition B: the worst case loading condition of a fully loaded tank at MAWP subject to an incremental change in the vertical and longitudinal forces of ±35% of the tank weight ±20% of the tank weight in the transverse direction uniformly distributed. The longitudinal force shall be applied as a decelerative force (Condition B1) and as an accelerative force (Condition B2). The accelerative force will be applied at the fifth wheel, and the decelerative force will be applied entirely at the rear wheels (Condition B1a) and at the fifth wheel (Condition B1b). For truck mounted tanks, the longitudinal forces shall be applied at the mounts.

If the acelerative force (B2) is to be applied only at the fifth wheel why it is shown at the figure at the rear wheels?

Sorry for the amount of questions, but I tried to make the possible answer as short as possible. Thank you for any inputs.

Regards