Global mobile crane heavyweight Demag has introduced the AC 450-7 all-terrain crane, which it calls a new standard among seven-axle mobile cranes.
The Zweibrücken, Germany-based manufacturer, which is part of the Tadano Group, said the basic idea when developing the new AC 450-7 was 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, while combining that with better performance. In terms of its dimensions, the AC 450-7 meets this criterion, having a carrier length of only 15.99m, an 8.45m outrigger base and a total length of 17.62m.
The AC 450-7 features an 80m main boom with a maximum lifting capacity of up to 195.5t. The main boom can be extended with a luffing jib with a maximum length of 81m. The crane’s maximum system length is 132m. The luffing jib can be divided up in three-metre segments from 24-81m.
Michael Klein, product marketing manager, Tadano Demag, said: “In other words, it doesn’t need more space than a six-axle crane at a work site, and yet it offers significantly better lifting capacities.”
The reason for the manufacturer designing a seven-axle crane was that the ”only way for the machine to be street-legal and meet our goals of having a longer boom and larger lifting capacities was for it to run on seven axles”, Klein explained. Despite mostly identical dimensions, the new AC 450-7 features considerably better performance characteristics when compared to cranes with six axles.
To make it easier to transport the luffing jib, two system dimensions are used, making it possible to slide the extension’s individual parts into each other. The Demag patented luffing jib rigging system makes setup especially fast, simple, and safe – a design that the new AC 450-7 shares with the Demag AC 300-6, AC 350-6, and AC 1000-9 models.
The AC 450-7 is also extremely versatile when it comes to extensions. In addition to the luffing jib, Tadano Demag also offers fixed jib configurations, even with an offset section, and also a runner.
An SSL Sideways Superlift system makes the new AC 450-7 part of the large crane category at Tadano Demag, and the company said it is using its new engineering design for the Sideways Superlift system for the first time ever on the AC 450-7.
According to the compnay, this 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, meaning that they are ultimately longer and accordingly well-suited to larger lifting capacities.
Tadano Demag says that this makes the AC 450-7 superior to other seven-axle cranes or even some eight-axle units in a number of boom positions. The AC 450-7 can lift 73.5t at a radius of 9m when equipped with a 60m main boom with an SSL configuration and 37.9t at a 13m radius when the boom is telescoped out completely to a length of 80m, and an outstanding 12.8t tonnes at a radius of 50m with this configuration.
The maximum counterweight for the AC 450-7 is 150t, consisting of a 20t base plate and redesigned counterweight plates that have been optimised in terms of swing radius, which is now only 5.60m. The counterweights are available as 10t and 5t plates, or a combination of the two, with the goal being to enable customers to optimise their transportation logistics. The base plate can be set up from the front – an advantage at work sites where space is tight and the corresponding transportation truck can only be positioned in front of the crane.
In addition, there is an optional counterweight frame available for the AC 450-7 that can be used to increase the swing radius in order to further increase the lifting capacity – especially when using an SSL configuration. Tadano Demag also offers various adapters that make it possible for customers to keep using existing counterweight slabs from their other larger AC or CC models with their new AC 450-7.
The AC 450-7 is available with two different carrier variants to meet axle load requirements all over the world. In the standard version it can be configured to travel under a 12t or 16.5t axle load limit, in both cases with the main boom in place. If the main boom is removed, the maximum axle load is reduced to a little over 9t with a gross vehicle weight below 48t.
The AC 450-7 is driven by a Mercedes-Benz engine with an output of 625hp. The diesel engine conforms to EU Stage V and Tier 4 Final emissions requirements, but is also compatible to Tier 3 emission norms, making it suitable for less regulated markets such as the Middle East.