Generators for Tower Cranes
What every tower crane operator should know about generators
Let your supplier do they heavy lifting
Tower Cranes are traditionally one of the more challenging technical aspects of diesel power generation. They have large start currents, various motor sizes, multiple winches and often create residual current and harmonic distortion.
Without boring anyone with the technical side of getting the sizing right, one thing that always gets overlooked when powering tower cranes is how much fuel can be saved on a project simply by selecting the correct engine manufacturer.
Below is a graph showing the annual fuel cost of a diesel generator powering a typical high rise 400 amp site. This includes a tower crane and double personnel/material hoist and represents a 6 day per week project. A 75% load rate is used to ensure like for like comparison. Loads could be higher or lower but the fuel benefits remain linear. I have used $1,20 per litre as a fuel price.
Engine’s A and B happen to be the engine’s you will most commonly find operating in this type of application. The rental cost of a machine this size in metro areas averages about $1,000 per week, and after maintenance, finance and disposal costs are taken into account, the cost of owning the same machine is much the same. As you can see, this effectively means, selecting the right engine provides greater savings in fuel costs than the entire cost of owning or renting the machine in most cases. IE: get your sizing and engine selection right, and your generator is free.
Add to this the environmental impact and it becomes even more compelling. Choosing Engine C over Engine A for example, is the equivalent of removing 32 family sized cars from the road, and that’s just on one site!
The obvious question is, why aren’t more people using this as a sales tactic with crane and construction companies? Well in the immortal words of Colin Sinton from Hirepool and Onsite fame, “turkeys aren’t very well going to vote for Christmas are they?”
What this means is, most suppliers are either engine manufacturers, or tied to manufacturers. They are “dealers,” for want of a better word. They are literally stuck with the fuel efficiency and carbon emission that’s handed to them and they have no choice but to sell the customer the machine they have.
I have written about powering tower cranes in the past because they present such an interesting opportunity to reduce costs, emissions and service issues. Crane owners represent some of the most “generator frustrated,” customers I meet during the course of a year, but there are ways to make your life a whole lot easier and cheaper with just a little bit of assistance from a specialised power company.
In my view, some of the innovative techniques companies like Hutchinson Builders have introduced in the area of power generation, distribution and emission reduction in recent years are a signal that the construction and lifting industry in general are putting themselves at the forefront of energy cost reduction and a commitment to the journey towards carbon neutrality.