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Structure steel erection - Crane Requirement

7 replies [Last post]
Kumar J
User offline. Last seen 1 year 3 weeks ago. Offline
Joined: 24 Jun 2001
Posts: 21
Dear Friends,

This is regarding Structural steel erection for process plant in Hydrocarbon (Oil & Gas)

1. Pipe Rack (21 m Height)
2. Technology structure (24 m)
3. Compressor shelter (15)
4. Sheeting

Can anyone will be able to guide me in planning for crane requirement. How many number of cranes are required to erect per day. may be in terms of Tons / Day. Crane productivity can be so many tons / day in erection, so many tons / day in material handling for erection.

Regards,
Kumar

Replies

Samer Zawaydeh
User offline. Last seen 29 weeks 1 day ago. Offline
Joined: 3 Aug 2008
Posts: 1664
Dear Joel,

What you are saying it true. It seems that kumar is trying to do a complete plan on his own and that is not correct.

But what we are trying to do here is to assist him in answering the correct questions to enable him to do his Schedule.

The Planning is a team effort done by the Construction team to complete the job. And the best people to determine the exact productivity rates are the supervisors at site. Unless you are at site and know exactly how the project is constructed you will not be able to make a constructable Schedule.

With kind regards,

Samer
Joel Gilbert
User offline. Last seen 1 year 34 weeks ago. Offline
Joined: 5 May 2003
Posts: 166
As a Planner it is not your job to determine what type of crane to use on a job, it is for a rigging superintendant that is trained to do that job and has the experience.

It is however your job to load the schedule activities with the cranes requirement that was determined by the qualified people. This will tell you in your histogram how many cranes you require per area for example for the length of your project


Samer Zawaydeh
User offline. Last seen 29 weeks 1 day ago. Offline
Joined: 3 Aug 2008
Posts: 1664
Dear Kumar,

This is a big project of 10,000MT. You will need to know what carnes your company will bring to site. Subsequently, you can plan the location for erection and the amount of tonnage that is available at each location covered by the crane.

You might have 1 or two big cranes in addition to several small ones.

Do you have any idea about the crane capacities that you have. If you have set your max erection capacities, then you much have some idea about the cranes, unless it is a randon number dividing the tonnage by the duration of the project!

With kind regards,

Samer
Kumar J
User offline. Last seen 1 year 3 weeks ago. Offline
Joined: 24 Jun 2001
Posts: 21
Dear Samer,

Thanks for the reply.

The weightage breakup of Pipe rack is as follows

1. Heavy - 3873 MT
2. Medium - 3808 MT
3. Light - 1540

Peak Month erection is 343 MT - Heavy, 330 MT - Medium, 136 MT - Light. Total lenght of pipe rack - 530 Meter.

I am looking for a thumb rule type wherein, i will be able to arrive at the approximate number of cranes required per month. From which i can draw crane deployment schedule.

As you have said, maximum crane requirement can be arrived at looking at the location of crane and height of pipe rack structure.

Sheeting i am taking your suggestion of 75-100 Sqm per crane in a month, right.

Thanks / Regards,
Kumar
Samer Zawaydeh
User offline. Last seen 29 weeks 1 day ago. Offline
Joined: 3 Aug 2008
Posts: 1664
Dear Bharath,

There are different factors that you need to determine in order to calculate the rate of installation:

1. Maximum piece weight
2. Type of steel; light, medium, heavy, extra heavy.
3. Location of your crane/s. You will need to obtain the load charts which you can download from the internet for major crane types.

Maybe you can answer the following questions.
1. What is the total weight of the piperack and its length.
2. What is the weight of the Technology structure
3. What is the weight of the Compressor Shelter.

4. Sheeting, you can complete on average 75-100m2 depending on weather, postion (vertical or horizontal) and accessability.

With kind regards,

Samer
Richard Spedding
User offline. Last seen 46 weeks 6 days ago. Offline
Joined: 20 Mar 2007
Posts: 127
Kumar

In producing a programme, you should allow for a crane (however big it is) to install about 24 pieces of steel per day between Ground and 20 metres above, going down to 21 pieces per day above that up to 40 metres above ground, for an 8 hour day. These are average rates allowing for offloading steel from lorries and laying out in installation sequence before erection.
You need to look at the plans and see where you can site cranes, and look at the steel and see where is the heaviest lift. From this you can determine how big a crane (or number of cranes) you will need. Then you obtain the dimensions of the size of crane you have decided you will need and plot that on the General Arrangement drawings. You can then work out how long you will need to erect the steelwork, and how many times you need to move the crane, or how many cranes you need to build the project out. You may even query the maximum size of piece and propose either increases or decreases to maximise efficiency
By all means ask the Construction Superintendent how he or she would build it, and what size / how many cranes they would use, but you need to constantly challenge what you are told by asking the right questions in order to see if you agree with the method and timing.
These are all planners tasks, while communicating with the remainder of the team. Just putting information into the programme (schedule) from others without question makes you a computer jockey not a planner.
Kumar J
User offline. Last seen 1 year 3 weeks ago. Offline
Joined: 24 Jun 2001
Posts: 21
Thanks Mr.Richard, i will do the same.