Both telecrawlers and rough terrain cranes have been competing with the smaller lattice boom cranes on many job sites and applications.

The market for them is growing. Oil and gas companies have been big users and the low energy prices of recent years have impacted sales; “There have been a few slow years” says Ed Hisrich, VP of sales at Tadano Mantis, “but as oil demand has increased so has crane demand; but generally it is infrastructure growth that is the driver. Telebooms have always been a consistent market for us.”

The advantages of the telescopic boom are many. Are they then completely eclipsing the traditional lattice boom in such fields as ground preparation, general construction, and civil engineering?

“Not so. Lattice booms have their market as well,” says Pat Collins, director of marketing at Link-Belt. “Lattice crawlers are simpler, to make and to operate, and therefore cheaper. And some things they do very well. But they have a limited range of jobs they can easily do. The more you can do with a tool, the better the tool you have – and on that ground telecrawlers and rough-terrain cranes deserve consideration.

“On arrival at a job site telescopic booms require minimal and much easier assembly.That gives one advantage. In construction, especially for foundation work, lattices are certainly giving ground.”

Speed is one factor in that: “With a lattice crane, if you are going to move it, you say to the team ‘I will come back in two hours and see how you are getting on.’ With a telecrawler, or a rough terrain, in eight or nine minutes the boom is retracted and off you go.” says Collins .

“The filter is that the smaller the lattice crane the more susceptible it is to being replaced by a telecrawler.”

For a purchasing manager, say for a hire fleet, choosing between the types – lattice, rough terrain or telecrawler – the logic of the decision process, says Collins, is this: “Ask yourself: Do I have the need for a telescopic crane? If, for you and the tasks you do, telescopic has the wider range of jobs it can do and of customers who would want it, then you investigate further.

“The next step is to ask ‘Can a rough terrain do these jobs at lower cost, or do I need to pay the extra for a telecrawler?’ Because rough terrains do have the cost advantage. Whether that is the deciding factor will depend on the purchaser.”

“Telecrawlers are generally more expensive than the equivalent size rough terrain cranes” says Hisrich. “But they continue to gain popularity. They are replacing lattice cranes in lifting applications, but also replacing rough terrain cranes in some markets as well.”

“The two biggest markets that the telecrawler is encroaching on are the lattice crawler and rubber tyred machines,” confirms Collins.

“If a rubber tyred – ie rough terrain – machine can do the job, that may be the best choice simply because of cost.”

Rough terrains have other advantages beside cost. “In some cases with the tyred rough terrain crane at a site or plant, time to travel to the laydown yard is measured in minutes rather than hours— a speed advantage for rough terrain over crawlers here” says Collins. “Certainly over multiple surfaces the rough terrain is much faster compared to a tracked crawler which needs pads to protect a finished concrete surface.”

“Drilling shafts and pile-driving are the biggest crossover areas where telecrawlers are encroaching on both lattices and rough terrains.There the great advantage of a telecrawler is its ability to pick and carry a load,” he says. “A telecrawler can pick a load at high height or radius, retract it on the boom and travel with it compactly. That is a huge advantage, certainly preferable to having to walk it with a long fixed boom, which is the lattice option.”

That pick-and-carry advantage remains when we compare the telecrawler against the rough terrain crane. “The truth is, a rough terrain’s pick-and-carry ability to do that is very limited compared to a telecrawler.”

With which Hisrich agrees: “The big difference between rough-terrain and telecrawlers is travel speed. A rough terrain can travel around a site at 40mph – but it cannot do that in pick-and-carry mode. For that, its capacity is reduced to 20% of its full lift load. It has to move very slowly, with the boom retracted and the load positioned between its tyres. For pick-and carry of the full load chart, rough terrain cranes are basically not functional.”

“A telecrawler on the other hand can carry 100% of its capacity load around the site; and the cranes we make can do that in any direction, at 360° radius. A rough terrain can basically only carry its load in the direction it is pointing, forward.”

“Rough terrain cranes can drive with loads at the hook” says Wolfgang Beringer, marketing manager at Liebherr. “But because of their large crawler base telecrawlers are even better. They can drive with higher loads.”

So for job-sites which require extensive lift-and-carry a telecrawler may be the crane of choice. This is all the more true if restricted spaces are an issue.

“With larger telescopics, on some jobs, reach and capacity are challenging the lattice crane” says Collins. “When a telescopic can do that it is really doing better. It can extend or retract its boom and work in a confined space – really jump around if you like.” As an example of a telecrawler doing exactly that he points to a ‘Hole in the wall’ job on a new rail link to Dallas Forth Worth airport featured in Cranes Today of March 2018. The duck and dive is a telescopic speciality.

Another factor that becomes relevant in restricted spaces is the outrigger. A rough terrain generally needs to deploy its outriggers; telecrawlers do not have them. The weight of the crawler chassis and the low centre of gravity that can be designed into a crawler suffice for stability. ‘A telecrawler does not need outriggers, so that gives a space advantage” says Collins. “That is a big deal, a huge difference. You can add in the time factor to deploy outriggers, and the labour, and ensuring adequate manpower in support for placing shoring mats and pontoons and so on.” Hisrich does not entirely agree.

“Most telecrawlers are designed to operate from level ground. Many manufacturers give their load charts for up to 0.3 degrees of slope. 0.3 degrees is not realistically attainable without civil engineering work to prepare a level lifting pad, so the customer either pays for site preparation or he de-rates the capacity of the crane to work on natural sloped ground. In reality, on any normal construction site the ground will not be anything like 0.3 degrees. Your writing-desk will not approach that level; water will not drain from anything so level. It sets an unrealistic goal for normal operation and that can give an inflated value of performance for a telecrawler.”

The outriggers on rough terrain cranes, on the other hand, are self-levelling, which sidesteps that problem and goes some way to restoring equality in the equation.

But “we design systems to operate out-of-level” says Hisrich; and points to a feature of Tadano telecrawlers which he claims as unique. “We publish our ‘flat ground’ load chart for a higher degree of slope, up to 1.5 degrees.” They also have standard load charts for operation on slopes up to 4 degrees.

Size also enters the decision equation here, in several ways. One is transportation to the worksite. “A rough terrain of 60t to 110t can be hauled in one load” says Hisrich. “A telecrawler that size takes three or four loads. But at 120t or larger both need disassembling and extra trucks.”

And both telecrawlers and rough-terrains are certainly getting bigger. “There have been trends for development of larger teleboom crawlers,” says Hisrich. The Tadano Mantis product line now ranges from 35t to 120t capacity.

“Telecrawlers have been getting bigger in recent years” confirms Beringer. “When we launched our 100t LTR 1100 some years ago it was the biggest in the market. At that time most competitors were 60t – 70t cranes.”

Which is not to say that the smaller versions are going out of fashion: “We also offer a 60t LTR as the market still demands smaller telecrawlers.”

There are also markets for very large telecrawlers indeed. “Windfarms need very large loads carried over long distances” says Collins.

“The support towers are huge components. Our TCC 2500 has walked right into that market, where it has replaced outrigger machines, whose siting has to be perfectly planned in advance.”

“A TCC 2500 has logged nearly 100 miles on a wind-farm in West Texas. Another has done 200 miles in eight months, at a huge laydown yard in Kansas handling nacelles – the turbine component at the top of the tower.” That site saw the TC 2500 working with a six-wheeler large rough terrain crane and a 25t lattice. “All were doing different things on the same job-site. A renting company will want all these capabilities and all these assets to offer to its core customers.”

“It is good to see a product not pigeon-holed to a job” says Collins. “Telecrawlers are going from niche to mainstream. Which leaves the question: why is a rough terrain such a good crane?

“The answer is that rubber tyres have an obvious advantage over a crawler – so if you can do it with a rough-terrain, then you should. It is the quickest, fastest, and therefore the right decision. And even if you have to use a work-around so that you can use your rough-terrain, then that is still the right way to go.

“A rental house should look at all these factors for a solution as to which types to buy. Telecrawlers are friendliest for rough or uneven terrain: certainly ten years ago that was the thinking. But now it is about space and speed. A telecrawler can give the best of all worlds. It can go around things, under things, expand its boom out, and it has the ability to pick and carry a load. It is the flexibility of telecrawlers that gives them the advantage. They are not so much ‘taking over’ from lattice cranes as eating into their market from the bottom up” says Collins.

“‘Show me first’ is a good buying philosophy. I find that when a customer has seen the telecrawler, he is taken with it. This is the customer who can look beyond price, who understands that labour and space cost money too. He adds it up and judges – and that customer goes for the telecrawler” he adds.

But it is not the end of the line for lattices. “Don’t write them off just yet” says Collins. “The economy of lattice is still there. There are some natural economic barriers that help to keep everyone honest. Its simplicity of operation and fewer moving parts make it good for remote locations.

“If I were a bridge-builder in the [US] mid-West, for example, I would want to see some very big numbers to move away from lattice.”

“We don’t see that rough terrain, telecrawlers and lattice boom crawlers are in hard competition” says Beringer. “Every crane type has its advantages, and the range of applications is big enough for all types.”

It seems that lattice cranes and rough terrains will not disappear, even if telecrawlers are increasingly finding new markets to compete in.