How to Choose the Right Crane for your Project

By Patrick Tarrant

As a construction superintendent, you are expected to have a basic understanding of the different types of cranes available for your project and the ability to determine if the crane on your job is the optimum choice.

When selecting a crane for a project, I like to start with the weight of the heaviest pick and the number of those picks. Once I know the weight, I then look at the distance of the pick from the center of rotation of the crane (radius). Then I move on to the site-specific issues that determine where I can place the crane and for how long.

Mobile hydraulic cranes are the most versatile for quick mobilization and removal but they are generally more expensive per day than lattice boom cranes. Mechanical trades typically use these to set equipment as they need them for just a day or two. They are often set up on public streets and are subject to DoT regulations.

If the project needs a crane on a day-to-day basis, however, a tower crane is often the machine of choice. If you have a tower crane on your job it should be a priority to make sure that it is made available to all trades that need to have material or equipment hoisted.

If a tower crane is not a viable option and a crane is needed every day, a crawler crane should be considered. It takes longer to set up than a truck-mounted hydraulic crane, but it has the advantage of being mobile on a site without removing counterweights or retracting outriggers. It can even move with a load on the hook which can be a major feature on sites with limited access.

Self-erecting cranes are being used more and more in North America. They are very common in Europe and they are a frequent sight on even the smallest projects. They have a very small footprint and can generally hoist material to 100 feet or more. They have a long reach but their capacities are generally less than 7,000 pounds.

Technology has brought knuckleboom cranes to the construction industry at boom lengths of 200 feet or more so they should be considered in any evaluation of suitability.

The superintendent is not expected to know every variable about every crane type but it’s important to be aware of the different types available. Find somebody knowledgeable in the crane business and get input from them. Find out what hoisting needs other trades have on the project and try to bundle them together to everyone’s benefit. There will be issues of responsibility and insurance but nothing that can’t be resolved with written releases and hold-harmless agreements. The benefit to the project will far outweigh the effort needed to consolidate this work.

A project superintendent will probably have different priorities than the subcontractor  using the crane, so it is important for him to have the ability to assess, in advance, the suitability of a particular crane for the task. What works for the sub will not necessarily work for the overall project.

On most jobs, there will be a need for more than one crane as different subs have different logistical issues. It is always better to minimize the number of mobilizations. Once a crane is set up it should be used to hoist everything possible at that time irrespective of the trade that needs it. This is where the superintendent can play a major role in coordination. Remember, the subs do not have contractual relationships with one another so there is a great need here for the super to step in and coordinate for everyone’s benefit.

Too many times I have seen situations where the super took the view that “it’s not my problem” and left the crane issues to others to solve when input from him would have been a win-win for all stakeholders.

I was recently involved in a project on the lower east side of Manhattan. The street is 30-feet wide and the sidewalk is 12-feet wide. A 14-floor, steel-framed building was being constructed. The city would not allow a full street closure as it was a major northbound route. The building was aligned with the property line on the inside of the sidewalk and was 120-feet deep. The city required an 11-foot-wide lane to be maintained at all times so there was no way a mobile hydraulic crane could be set up on the street.

The developer was told by NYC DoT that they should use a tower crane located on the property but that would have required a bay being left open at each floor until the job was done and the cost of a tower crane would have been more than $2 million.

I proposed using a crawler crane that can use a main boom of 140 feet set at 90 degrees with a luffing jib of 140 feet that can luff up to a minimum radius of 34 feet. We were five feet off the face of the building with the boom when we left the 11-foot lane open, but the job got built using this crane at about a third of the cost of a tower crane.

On another current project, we are using a large crawler crane set up on mats to erect a modular building on a very tight site. The access point for the utilities is under the mats so, until the crawler is dismantled and the mats are removed, the contractor cannot start on the utilities installation. The top three floors are not modular so the weight of the picks is a lot less. Here I proposed setting a mini crane on the 17^th floor, which is the floor above the highest modules so we can dismantle the crawler once the last module is picked. This allows the utilities to be installed while the top three floors are being erected by the mini crane, which can be disassembled and taken down on the hoist when the project is completed.

It’s important to involve the right people on the project at the earliest possible time as their input and experience can suggest remedies that may not be apparent to people that do not spend every day immersed in crane logistics.

Patrick Tarrant is the founder and CEO of Crane Management. He is a Certified Hoist Operator, Master Rigger, AWS Welding Inspector and is trained in all areas of crane operations. For more info, visit: http://cranemgm.com.