ATs: All that and more

15 April 2008

New York-based Bay Crane has developed a strong customer base for its Liebherr ATs

New York-based Bay Crane has developed a strong customer base for its Liebherr ATs

In 2006, at least eight new all terrain cranes were introduced to the US market, with the 200 to 275 ton class crane apparently the most popular. While production departments continue to struggle to fill orders, engineering teams are working on new designs. For example, two 1,100 ton capacity machines are in development.

Historically a crane designed for the European market, ATs are now a mainstay in the fleets of most American crane rental companies. The critical questions of transport, reach, lift capabilities and ease of set-up have been answered for US crane owners, who are using these machines on projects that require precision, mobility and power. While ATs have not replaced any given type of crane in the market, they have earned their place among the typically more American-styled or American-produced cranes. Interestingly, every AT sold in the US is built in Europe, Japan or China.

Most everyone associated with marketing ATs in North America are optimistic about the market for these machines, and even if there is a slowdown in construction activity in the next year, the interest in these machines continues to grow.

“[Demand] has increased considerably,” says John Turner with Terex-Demag. “The fiexibility of these type of machines, 'all-terrains,' to drive to and then to get to the job sites allows them to work in conditions worse than allowed for the typical truck crane style of machine. The increase of modular housing utilizes these cranes well. With the overall increase in construction as well as fieet upgrades and demand [is strong for] these units over truck cranes and crawlers. This market is strong for the remainder of this year as well as next year. Machine sales are good for 2007.”

New machines abound

The biggest news in this product class is the number of new machines on the market and the outlook is good for more new models. The most recent ATs introduced into the North American market have been from Tadano Faun, which produces ATs for Tadano America and Link-Belt Construction Equipment.

In October 2006, Link-Belt unveiled its new 250 ton (220 metric ton) ATC-3250. Th is new model has all the attributes of the Link-Belt ATC-3200 but with more power and strength. The ATC-3250 brings the Link-Belt AT offering to three models, ranging in capacity from 130 to 250 tons. Link-Belt has chosen to work in the higher capacity realm of the AT market, making sure not to encroach on its burgeoning RT and truck crane market.

The ATC-3250 has a 43.3 - 223.1 foot (13.2 -68.0 meter), full power, seven-section, latching boom. The sections extend independently by means of one double acting, single-stage hydraulic cylinder. Four pinned positions of 0%, 46%, 92%, and 100% on each section provide 38 extend combinations for good capacity when varying the extensions of the telescoping sections.

A 17.7 - 43.3-foot (5.4 - 13.2 m) two-piece, lattice fly and four lattice fly extensions are available as options for additional reach. Each of the extensions is 19.7 feet (6.0 m) and extends the fly length to 63 feet (19.2 m), 82.7 feet (25.2 m), 102.4 feet (31.2 m), and 122.1 feet (37.2 m). All of these attachment combinations have offset positions of 0, 20, and 40 degrees. The 43.3 foot (13.2 m) attachment with all four lattice extensions used in combination with the main boom reaches a maximum tip height of 358 feet (109.1 m).

The ATC-3250 features the LoadCom load radius compensating system, which compensates for boom defiection under load. The LoadCom feature assists the operator in eliminating the guess work, so that as a load lifts, the LoadCom system automatically compensates for any increase in radius, as a result of boom defiection, by activating the boom hoist.

With acoustical insulation, the galvaneal cab has a tilting capsule for high boom angle lifting. This capsule, consisting of the seat, joysticks, pedals, and main console, tilts independently of the cab. The controls and instrumentation are ergonomically designed with outrigger controls in the operator's cab. Two electric-over-hydraulic, dual-axis levers with fine metering capability control the winches, boom hoist, and swing. Heating and air conditioning, a cabin pre-heater with a pre-settable timer, AM/FM stereo with CD player, power front window, foodlights, and an integrated cab walk are standard.

Axial piston, constant displacement motors drive the main (front) and auxiliary (rear) winches, which have final layer and third wrap indicators. The main and auxiliary grooved hoist drums contain 1,148 feet (350 m)of 0.83 inch (21 mm) wire rope.

Maximum line pull for each winch is 24,504 pounds (11,115 kg) and the maximum line speed is 508 ft/min (154.7 m/min).

The ATC-3250 has a 530 horsepower (390 kW) Mercedes-Benz engine and a ZF AS-Tronic automated 16-speed manual transmission that delivers a top speed of 52.8 mph (85.0 km/h). With five axles, the ATC-3250 has a 10x8x8 drive/steer configuration. The machine can handle grades of 61% and a third-axle lift system provides more inter-bridge spacing to comply with certain transportation requirements found throughout North America.

The primary steering varies with the speed of the crane: below 15.5 mph (25 km/h), axles 1, 2, 4, and 5 steer in combination. As the speed increases, axle 4 and then axle 5 sequentially return to center until axles 1 and 2 become the only two axles steered. There are also five additional steering modes, including independent front, combination, crab, independent rear, and a temporary crab steering mode. The temporary crab mode allows the crane to drive away from an obstruction like a curb or a wall.

Best sellers

Terex-Demag has made a good impression on the North American market, selling one of the best known AT product lines. The five-axle, 170 ton capacity AC 140 is among the best selling ATs in the US, according to sources with Terex in the US.

Early in 2006 TerexDemag upgraded its AC 55 to the AC 55-1. Improvements include a new boom telescoping system that reduces the axle loads and enhances lifting capacity. With the boom telescoped to 131 feet (40 m) and set at a 33 foot (10 m) radius, the increase in lifting capacity over the outgoing model is more than 20%.

Telescoping and setup times of the AC 55-1's fully hydraulic boom are half of that of a pinned boom, and the boom can be telescoped under load, the manufacturer says. A further benefit is a lower weight that reduces the front axle load - the crane will run at 13.2 tons (12 metric tons) per axle, with 5.7 tons (5.15 tonnes) of counterweight, 49.2 feet (15 m) main boom extension and hook blocks, according to the company.

Lifting capacity is increased the most (by between 10 and 20%) on longer combination lengths at medium operating radii. A new option is a 26.2 or 49.2 feet (8 or 15 m) hydraulically offsettable boom extension that can be controlled from the operator cab under full load. This option is also available on the AC 35, AC 35L and AC 55L.

At a customer event at its Zweibrücken factory in Germany in July 2006, TerexDemag announced it is developing a 1,000 metric tonne (1,100 US ton) capacity wheeled mobile telescopic crane. With a maximum load moment of around 3,000 tonne-metres, the nine-axle AC 1000/9 will be the world's strongest boom-on wheeled telescopic crane, according to the manufacturer. The machine will travel wiThits 164 foot (50 m) boom and front outrigger at 13.2 tons (12 tonnes) per axle. Minimum and maximum outrigger base spreads will be 32.8 by 32.8 feet (10 by 10 m) and 44.3 by 44.3 feet (13.5 x 13.5 m). The maximum lufing fly jib will be 413.4 feet (126 m). The AC 1000/9 is scheduled for launch in 2008 and a boom-of version is under consideration.

Also under development at Terex-Demag is the AC 100/4, a four-axle all terrain mobile, which will likely be first seen in iron at April's Bauma exhibition in Germany. The new crane has a five section 164 foot (50 m) pinned boom for a strong lifting chart. At a 32.8 foot (10 m) radius with the boom fully extended, the preliminary chart shows it will lift 13.2 tons (12 tonnes). Maximum boom and jib combination will be 226.4 feet (69 m). The carrier is 8.4 feet (2.55 m) wide and 33.8 feet (10.3 m) long. Overall length, including the boom overhang is 43 feet (13.1 m).

Also expected in iron at Bauma in Munich is the 1,100 ton capacity Liebherr LTM 11000-9.1, under development at the Liebherr-Werk Ehingen factory in Germany. It will have two telescopic boom options - a long one (as the engineering design develops it is getting longer than the initially projected 60 m) and a short one for use with lufing jib.

While it produces among the largest ranges of ATs in the world, Liebherr tends to focus  on the higher capacity machines - 180 through 600 ton classes - in North America. The cranes that have developed a customer base in the US include the LTM 1160-5.1, LTM 1200-5.1, LTM 1220-5.2, LTM 1250-6.1, LTM 1300-6.1, LTM 1400-7.1 and LTM 1500-8.1. According to sources at Liebherr, the 265 ton LTM 1220-5.2 is the company's best selling five-axle model while the 500 ton capacity LTM 1400-7.1 is the most sought after Liebherr AT.

Grove is aggressive

Grove was the most aggressive in AT product introductions in 2006 bringing four new models to the market. Intermat in Paris was the stage for four new ATs, the 35 ton capacity GMK2035E, the 100ton capacity GMK4100B, the 115 ton GMK4115 and the 275 ton GMK5275.

Largest of these new models is the GMK5275, which is known as the GMK5220 outside the US. Th is five-axle crane has a capacity rating of 275 tons (220 tonnes) and a 223 foot (68 m) main boom. The crane has one of the strongest lifting charts of five-axle cranes on the market with a 15.4 ton (14 tonne) capacity on its fully extended boom.

The higher capacity for this crane is the result of the newly enhanced MegaForm boom profile. The crane also has a stronger but lighter carrier and a new hydraulic electronic steering system. The “steer by wire” system is said to reduce tire ware and improve drivability. The crane carrier has a 420 kW Mercedes engine and Allison transmission.

The GMK5275 has a 39 to 69 foot (12 to 21 m) bi-fold lufing swingaway, which can accommodate up to two 26.2 foot (8 m) inserts to provide a maximum tip height of 354.3 feet (108 m). The jib can be hydraulically ofset between 5 and 40 degrees using controls in the crane cab.

Also new from Grove this year is the GMK4100B, which is known as the GMK4080-1 outside the US. With a 100 ton (80 tonne) rating, the GMK4100B has a six-section 167 foot (51 m) main boom. It lifts 7.3 tons (6.6 tonnes) at its maximum boom point of 167 feet (51 m) and out to a radius of 65.6 feet (20 m).

Additional equipment on the GMK4100B includes a multi-function remote control that allows the operator to execute the outriggers and swing-away jib from the safest and most convenient position outside the cab.

Among the more popular ATs in Grove's product line is the GMK6250L, which is known as the GMK6220-L outside the US, and is rated at 250 tons.

Tadano 'G' series

New from Tadano America is the five-axle ATF 220G-5, like the Link-Belt ATC-3250, with a 223.1 foot (68 m), seven section telescopic boom that can be extended under partial load. Its 250 ton (220 tonne) maximu capacity is at 2.5 m radius over the rear, while at 3.0 m it is 201 tons (182.5 tonnes) through 360 degrees. Boom extensions to 122.5 feet (37.2 m) are available with an integral 17.7 (5.4 m) ofsettable heavy duty jib.

The two-engine crane has Mercedes Benz diesels - 150 kW in the upper and 390 kW in the carrier. Drive/steer is 10 x 8 x 8, maximum travel speed is 85 km/h and maximum gradeability is 61% on 16.00 R25 tires. The transmission is a 16-speed ZF AS-Tronic wiThintarder and two stage transfer box. The carrier is 44.06 feet (13.43 m) long and the overall lengThis 49.7 feet (15.11 m). It is 9.84 feet (3.0 m) wide on 16.00 R25 tires.

Tadano launched its ATF 65G-4 in late 2005, the third in its “G” or global series of all terrain cranes introduced in 2004. As the name suggests, the global element of the design means the inclusion of specifications and features that consider the difierent regulations of markets around the world, including carrier width, axle spacing and overhangs. The G series has been well received in North America.

The four axle ATF 65-G-4 comes within the 13.23 (12 tonne) per axle limit with a double folding jib, 8 x 6 drive, the full 13.23 (12 tonne) of counterweight and two hook blocks. The 144.36 foot (44 m) single cylinder boom is lighter and has a new profle for safer lifts and a stronge chart. Standard drive/steer is 8 x 6 while 8 x 8 is an option. Also fitted is the automatic electro-hydraulic steering system used on the other G-series models, the ATF 45-3 and ATF 60-3 for optimal turning radii and maneuverability. All axles are steered, offering crab on site, and the rear axles three and four can be manually steered independently of the two front axles. On the road the first and second axles are steered, assisted by the fourth axle, which is electronically steered at up t 15 mph (25 km/h) in line with road regulations.


Receive the information you need when you need it through our world-leading magazines, newsletters and daily briefings.

Sign up