Deciding which crane is right for your objectives can be an overwhelming task, as the range of options available is limitless! There is an enormous variety of cranes, each designed for a specific function or use. One example is tower cranes - these are fixed to the ground in large concrete footings or use weighted city bases when a concrete footer isn't needed.
Tower cranes are commonly used in the construction of tall buildings and are attached at various floors as the building rises. They are unique as they have the ability to climb the building as it rises. Tower cranes can add their own tower sections when equipped with a climber section. The climber allows the crane to jack the tower up enough to add one section of tower per move.
The climber section also gives the crane the ability to lower its self-back down the side of a building once the building is completed. Once it is at a lower elevation, a mobile crane can disassemble the crane and load it out until its gone as if it was never there.
Selecting the right crane for the job definitely requires preliminary preparation and planning but is an absolutely essential process, as it not only ensures your construction site is safe for workers and the public, but can also help you reduce costs and inefficiency, keeping your project on track, budget and schedule.
Three factors you should consider when choosing a crane
1. The duration of the job, and the size and weight of the material you will be lifting
Cranes have different specifications, capacities and functionalities. Understanding what your project requires from a crane will help you select equipment that can best meet your projects demands and will quickly narrow down your options.
Load charts will also detail vital features of the crane such as boom length and the rated capacity - this is the gross weight that any crane can lift at a given radius (distance).
When determining the right crane, the crane hook block and or ball as well as all rigging /cable must be deducted from this gross capacity to arrive at the safest crane for your particular project.
The manufacturers' charts will give you the exact specifications and dimensions of the machine. These graphs will allow you to calculate your maximum lift within any given radius. Getting this right will help you avoid selecting a crane with too little capacity, and will insure it will fit into your job site with no obstructions. All of these factors insure that your job will be profitable and go as planned.
2. How equipment will be transported
The question of how the equipment will be transported could be initially overlooked, however, it is a critical consideration.
Broadly speaking, cranes can be classified as either mobile, rough terrain/crawler or tower - all with different transportation methods. Permitting for city and state laws are all factors in the transportation of cranes and heavy equipment. The permit routing may take the crane in what would seem like an indirect route. This is done in order to avoid a low capacity or low clearance bridge or a roadway that is not sufficient for large loads or trailers to avoid accidents or other traffic issues such as road construction.
3. The conditions of the construction site
The condition and terrain of the construction site also have a bearing on the type of crane you should be going after. Understanding weather conditions, spatial constraints and the ground conditions of your site will give you great insight into which equipment will help you meet your objectives with efficiency.
For example, rough terrain cranes are best suited to off-road construction sites as they are best equipped to deal with complicated ground conditions compared to all terrain cranes. The degree of mobility you require will also dictate the type of equipment needed. For instance, if your project requires flexibility and precise delivery in tight spaces, a mini-crane may be right for you.
Types of Cranes
A brief overview of commonly used cranes and their functions.
Tower cranes are typically used in the construction of tall buildings. As a fixed structure, its stability comes from being bolted to concrete slabs and provides a combination of both awe-provoking height and great lifting capacity, typically between eight and 35 tons. Tower cranes are great for long-term projects!
Due to the sheer size and reach of tower cranes, extra precautions must be taken for safety and specially-skilled operators are required to man the machine. Adverse weather conditions can also hamper the schedule.
- Potain - MDT 368 - 17 (tonnage)
- Terex - CTT182-8 - 9 (tonnage)
- Terex Comedil - CTT-561A - 22 (tonnage)
- Wolffkran - 700B - 55 (tonnage)
Crawler cranes are mounted on moveable tracks. These tracks are specially designed to be used on multiple ground types including soft terrains. Due to the tracks and excellent counterweight control, crawler cranes are able to lift extremely heavy loads, typically from 80 to 825 tons. Additionally, they have the ability to safely transport materials around the construction site with ease. With such vast lifting capacities, they can often be bulky, difficult to transport to location and expensive to assemble and dismantle. Therefore, crawler cranes are best suited for long-term projects.
- Manitowoc 2250 - 300 (tonnage)
- Manitowoc 18000 - 660 (tonnage)
- Link-Belt - LS-138HII - 80 (tonnage)
- Manitowoc - 31000 - 2535 (tonnage)
HTC truck type /all-terrain cranes
These cranes are used for short-term jobs where the lift requirements are too large for a boom truck yet are not long enough in duration or heavy enough to justify a crawler crane.
You will see these cranes on a daily basis as they travel the roads and highways just as the daily commuter does on their daily activities. These cranes are best suited for commercial work and in Industrial sites /hospitals/shopping mall HVAC repair or short-term bridge construction. These machines average in size from 30-ton capacity to over 1000 tons. These cranes on average are the bread and butter of most crane companies' business and how most are started initially.
- Grove TMS 540 - 40 (tonnage)
- Link Belt HTC 8690 - 90 (tonnage)
- Grove GMK 7550 - 550 (tonnage)
As well as being versatile and reliable, boom trucks are designed to provide important functions that, when combined, are extremely useful for most daily construction sites. Boom trucks are fitted with a hydraulic crane and a flat deck hauling area which allows you to lift light to medium size equipment and material. They also have the ability to transport light miscellanous equipment around a job site and to other locations as many trucks are able to travel at highway speeds.
- JLG - 2250-JBT- 23 (tonnage)
- Manitex - 2284 - 22 (tonnage)
- Terex - TC-4485 - 22 (tonnage)
Carefully considering your options when renting or buying a crane can help you avoid choosing equipment that is ill-suited for the job at hand. Incorrect selection can increase costs, affect your schedule and even jeopardise the safety of your staff and the public. In order to make an informed choice, it is always best to consult a crane rental company such as Maxim Crane Works L.P.
Maxim Crane is US-based, coast-to-coast provider of crane rental and lifting services.