Lifting/Tailing Lug for Half Section

[Rocky3640]

Hello,
I'm designing a tray tower 13 ft Dia and 0.875" thk. Due to some space constraint in the field, this tower needs to be cut into two halves. I need some insight for evaluating stress in the design of tailing lug for top section and trunnion for bottom section as these will be the open part during shipping. Has anybody been in this situation?

 

[dhengr]

Rocky3640:
It never ceases to amaze me how little important engineering and design info. you people seem to think you should provide, if you want a meaningful discussion and solution to your problem. These details are important for a good, economical and practical solution. What are the lengths of the two pieces and their weights? What’s the joint btwn. the two halves, bolted flanges or a field welded joint? What crane cap’ys.,etc., etc. Some sketches of the pieces and the lay-of-the-land would be helpful in understanding your problem. What do you think the lifting trunnions and tailing lugs should look like, start your design and show it here, so we have something to discuss and critique.

When you do something like you are proposing, you probably have to brace the two pieces for manufacturing, handling and transport, in any case. So design this bracing in (or on) the ends of the two halves to serve both functions. On the bottom half, this bracing will have to react the trunnion loads from the entire weight of the piece, in the final analysis, and the uprighting loads during that process. On the upper half the tailing lugs are needed during the uprighting, but then they could be removed prior to the final lift and placement of the upper half. Thus, the top trunnions and tailing lugs might actually be built into your bracing frames. And, these bracing frames could bear on the inside (the i.d.) of the vessel and be bolted to the flanges, if there are flanges. This bolting might not be enough for the top lifting trunnions, but might be sufficient for the tailing lug loading.

 

[Rocky3640]

Dhengr and MJCronin,
Agreed with you for not providing enough information and does not make sense to expect what I need without providing the real scenario.
We are fabricating the whole tower, perform hydro test and cut the tower into halves for shipping. The bottom section (77’ tall and weighs around 225,000 lbs) is installed on the field and top section (56’ tall and 160,000 lbs) will be installed and welded in the vertical position.
I have designed lifting trunnion for both section with 24” OD and 1.125” thk with an end cap and a guide cap both 1.125” thk. I’m planning to use (1) 20” pipe for bracing on the lifting trunnion for bottom section. There will be dual tail lugs for both section with W18 beam going across.
The main thing I’m concerned is the tailing design for top section and lifting trunnion for bottom section as these ends will be opened during rigging. Also not sure how the bracing design should be done to overcome the stresses in those areas.
Appreciate your input.