New Demag AC 450-7 Sets Benchmark for 7 Axle All-Terrain
Nov. 18, 2020 - Setting new standards on seven axles – certainly not a humble goal for the engineers at Tadano Demag when they started their work on the new AC 450-7 all terrain crane.
The crane manufacturer from Zweibrücken, Germany has met that goal by offering a new seven-axle crane that features forward-looking solutions and impressive technical specifications.
The new model is available in the Americas right now. The basic idea when developing the new AC 450-7 was both simple and demanding: Tadano Demag wanted to “give wheels” to a more powerful alternative to its existing six-axle cranes, with the objective of keeping it as compact as its counterparts despite the additional axle.
A second important target was delivering significantly better performance.
The AC 450-7 met its footprint goal. Its carrier measures just 52’6” long, and its total length is just 57’10”. The fully extended outriggers measure 27’9” In other words, it needs only as much space as a six-axle crane, yet offers better lifting capacities, said Demag Product Marketing Manager Michael Klein.
Klein went on to explain that the seven-axle chassis was needed to make the crane street-legal while providing a longer boom and stronger lifting capacities. Despite mostly identical dimensions, the new AC 450-7 features considerably better performance than six-axle ATs.
In fact, the “new kid on the block” features a 262.5’ main boom with a maximum lifting capacity of up to 212.8 USt. If the boom’s length is not sufficient, the crane’s reach can be extended by adding a luffing jib that itself can be up to 265.7’. The crane’s maximum boom-and-jib length is 433’. The luffing jib can be assembled in 9.8’ increments from 78.7’ to 265.7’.
To make transportation more efficient, the luffing jib is designed so that some sections can nest inside others to minimize transport volume and reduce the number of trucks needed. Tadano Demag also offers fixed jib configuration, even with an offset section, as well as a runner.
New SSL Superlift Design
The SSL Sideways Superlift system not only makes the new AC 450-7 part of the large crane category at Tadano Demag. It also means that the latter will represent more than one debut: Tadano Demag is using its new engineering design for the Sideways Superlift system for the first time ever on the AC 450-7.
The new design is a critical enhancement to the well-known Demag SSL solution, with the Superlift arms now being mounted all the way in the front, on the head of the base section. That makes them longer and well-suited to larger lifting capacities.
The AC 450-7 is considerably superior to other seven-axle cranes – and even some eight-axle units -- in a number of boom positions. More specifically, the AC 450-7 can lift 80.6 USt at a radius of 30’ when equipped with a 196.2’ main boom with an SSL configuration; 39.7 USt at a 48’ radius when the boom is telescoped out to its full 262.5’ length; and an outstanding 14.5 USt at a radius of 160’ with that configuration.
The new Superlift design also offers better functionality and handling. It requires only one wire rope line to connect the main boom head to the SSL arm. In addition, the SSL arms are pinned hydraulically on the main boom, which reduces manual work for securing the arms and the associated work at height.
Improved Counterweight Design
The maximum counterweight for the AC 450-7 is 165 USt. It consists of a 22 USt base plate and redesigned counterweight plates that have been optimized in terms of swing radius, which is now only 18.4’. To optimize transportation options, the counterweight plates are available as 11 USt plates, 5.5 USt plates, or a combination of the two. Also practical: The base plate can be set up from the front – an advantage particularly beneficial at work sites where space is tight and the transportation truck can only be positioned in front of the crane. “This solution, too, was the result of us listening to customers’ explicit requests,” Klein highlights.
In addition, an optional counterweight frame can lengthen the counterweight tailswing to further increase lifting capacity. Also, Tadano Demag offers adapters that let customers use existing counterweight slabs from other larger AC or CC models with the new AC 450-7.
Demag Surround View
At 27.7’, the outrigger base is also at the level of a 6-axle crane. But the AC 450-7 has five outrigger widths in order to offer greater setup flexibility, particularly in confined spaces.
The new optional Demag Surround View makes it easier for the crane operator to position the AC 450-7. The patented system’s six cameras display the possible outreach of the outriggers as well as the tail swing radius in a computer-aided display.
"Demag Surround View displays in the carrier cabin the different outrigger widths so the crane operator can position the crane to extend all outriggers sufficiently and ensure the required slewing radius. This reduces time-consuming measuring and trial and error when looking for a location, so that the crane can be ready for operation more quickly," explains Klein.
Demag Surround View also supports the driver on the way to the lift site. The cameras can deliver images of the crane side areas when turning, helping the crane driver to see cyclists, pedestrians, or any obstacles. This function is activated automatically when the turn signal is operated. “This new feature is a real highlight,” says Klein. “We discussed it with several customers and received enthusiastic feedback for it.”
The well-established IC-1 Plus control system provides maximum available lifting capacity, as it determines the crane’s lifting capacity for every boom position as a function of the superstructure’s slewing angle in real time. That means that the maximum available lifting capacity can be used with any outrigger configuration, including asymmetrical. In addition to the IC-1 Plus control system, the crane is available with the IC-1 Remote, making it possible to remotely read and diagnose all important crane data.
Flexible Traveling Capabilities
The AC 450-7 is available with two carrier variants to meet axle load requirements all over the world. In the standard version, the AC 450-7 can be configured to travel under a 13.2 USt or 18.2 USt axle-load limit, in both cases with the boom in place. Removing the boom reduces the maximum axle load to just over 9.9 USt and a gross vehicle weight below 52.9 USt.
Tadano Demag again listened carefully to customers and now offers a special carrier version with removable rear outrigger box. “With this solution, we provide our customers another possibility to reduce gross vehicle weight,” Klein explains. “The quick connections allow customers to remove the outrigger box with ease,” Klein said.
Wearless and Powerful Start-up and Safe Braking
The AC 450-7 The AC 450-7 is driven by a 625-hp Mercedes-Benz engine that meets EU Stage V and Tier 4 Final emissions requirements, but is also compatible with Tier 3.
The Mercedes-Benz transmission has a turbo retarder clutch for wearless and powerful start-up, as well as an integrated high-performance primary retarder.
Drivers benefit from sensitive starting and shunting and do not have to worry about temperature. Four axles drive, and all seven steer. That makes the AC 450-7 so maneuverable that it can navigate tight work sites at least as well as a six-axle unit.
Powerful like an 8-axle crane, compact like a 6-axle crane, and incorporating the latest Demag technology: the AC 450-7 is the new benchmark on 7 axles.
