A harbour mobile crane (HMC) is the Swiss army knife of a port operator’s fleet, able to be turned to a wide range of roles, both onshore and off. With the right attachments selected, the same crane may work on containers, bulk materials, or project cargo. They may be deployed anywhere that a port operates—at the order stage, the customer can choose the same crane mounted on a rubber-tyred chassis, a rail mounted portal, or a pontoon.
Manufacturers around the world include Liebherr, Gottwald and Sennebogen in Germany, Italgru and Reggiane in Italy, and Japan’s Mitsubishi. The common design feature of all these cranes is a fixed tower rising vertically from the crane’s bottom slewing base, with a hydraulic luffing boom extending forwards, allowing the crane to reach into a ship’s deck, raise a load, and then rotate to deposit it. Typically, they are fitted with a diesel electric power pack, with an option of additionally powering the cranes from an external electric power supply.
Peter Klein, Gottwald head of marketing, says, “Harbour mobile cranes are used in all types and sizes of ports. At medium ports, where bulk materials, containers and cargo are coming in, they can be fitted with spreaders, slings and other lifting gear as needed: they are very versatile. You can change lifting gear very quickly, in order to handle a wide variety of cargo. They’re also very mobile—you can reach anywhere in the port.”
Ian Schofield, group engineering director, Associated British Ports, says, “We use mobile harbour cranes for a wide range of operations, from bulks to general cargo to containers. We now have HMCs operating in each of our five operating regions, and currently have a fleet of 23 HMCs in total. Of these cranes, we have purchased mainly Gottwald and Liebherr in similar number, operating Liebherr LHM 70s through to LHM 320s, and Gottwald HMK 170s to HMK 320s, and the new generation of HSK 360 portals.”
Thomas Bachmann, Liebherr head of marketing, mobile harbour cranes and reachstackers, explains how the cranes can be deployed at different size ports, “The jobs these cranes are fulfilling are multi-purpose—they can handle virtually any sort of job. On ports where container rates are less than 100,000teu (20-foot container equivalents) µper year, mobile harbour cranes can work on their own.”
Bachmann continues, “When container rates reach more than this, or as the port becomes more dedicated to bulk handling, ship–to-shore gantries or specialist bulk handling equipment will be used. However, we have delivered HMCs to bigger ports such as Rotterdam or Antwerp in the Netherlands, not just smaller harbours and river ports. They can be used at bigger ports to support ship-to-shore gantries.”
This flexibility makes harbour mobile cranes popular worldwide. Bachmann says, “The most important market for us has always been Europe, with Spain, the UK, Ireland, and Germany leading demand. We’ve seen HMCs selling well in India over the last two years, and are seeing a recent second boom in South America. Most of the customers in these two regions are container terminals. Since the economies have recovered, they have budgets to purchase new cranes. There is also tax relief and state funding available for crane purchases in many of these markets.”
Klein agrees that emerging economies are a booming market for harbour mobile cranes: “We’ve sold to more than 80 countries since we started building these cranes, in 1956. Demand depends on the prosperity of the regions we’re selling to—regions that are doing better tend to buy more cranes. Africa was strong in 2006.”
Key features
For customers, the key feature of any crane will be lifting capacity, outreach, and hook height, both above and below the quay to reach deep into the ship’s hold. Liebherr’s LHM series ranges from the 40t (44 US ton) LHM 100, to the new 208t (229 US ton) LHM 600. Gottwald’s Generation 5 cranes offer capacities from 74t to 200t. Italgru offers capacities from the 20t GS 180p through to the 120t GS 2400 P, while fellow Italian manufacturer Reggiane offers cranes of between 20t and 100t.
The LHM 100, fitted with a hook, can lift 9.2t (10.1 US ton) at 30m (98ft) jib-end to a maximum height of 17m above or 15m below the quay. At the other end of Liebherr’s range, the new LHM 600 can lift its maximum 208t load at a radius of 17m, or 48t a distance of 58m. It can reach over 19 containers, stacked five containers high on the deck. Fitted with a spreader, it can lift a 41t container 52m from the quay.
Gottwald’s Generation 5 cranes can achieve hook heights of 12m below the quay, or 40m above. Models 6 and 7 of Generation 5 have a radius of operation between 11m-51m from the crane, while the Model 8 can work at a radius between 12m-52m. Both Gottwald and Liebherr offer cranes with line speeds of up to 120m/min (390ft/min), luffing speeds of 100m/min, and slewing speeds of up to 1.6 rpm.
In the HMC market, two other figures also rate highly. The first of these is the boom pivot point, the point at which the luffing boom is attached to the tower. Klein explains why Gottwald’s new Generation 5 series of HMCs now feature a taller tower: “Older container ships used to stack containers four high, but now they are going up to six containers high. By making the tower higher, we’ve raised the boom pivot point, meaning the crane can come right up to the ship, and put the cabin higher, increasing the operator’s visibility.”
The Generation 5 cranes feature a boom pivot point of 23m, with the crane cab offering the operator an eye level of between 26m and 33m (in the four rope grab variant of the largest cranes). Liebherr’s LHM 100 has a boom pivot point 10m high, and an operator eye level of 13.5m; the LHM 320 offers an 18m pivot point and a 24m eye level; the LHM 600 boom is 19m high, with the operator’s eye level at 25m.
A second important feature is the rate at which the crane can perform duty operations. Klein says, “In bulk handling, we’ve got grab cranes that can move 1,500t, or more, in an hour – this allows us to keep with specialist bulk handling equipment. Specialist equipment can be expensive, both in terms of the investment in new equipment and in dock infrastructure, so harbour mobile cranes can be a cheaper alternative.” Gottwald grab cranes move bulk loads with a four-rope grab, pulled by two two-rope hoists and powered by a 1,100kW (1,500hp) diesel electric engine.
A key element of the flexibility of these cranes is that customers can choose from a range of options when they make their order. Klein says, “We can fit different towers, change hoisting speeds and so forth. We have an advance order program: rather than waiting for customers, we plan for the number of cranes the market will need. When we get an order, we can install options, such as different diesel generators, as the customer wishes. This means that, if the crane is ready, we can deliver cranes in a matter of weeks to local customers. Delays in delivery come in because of transport problems for customer further abroad, due to restricted transport capacities.”
Liebherr also builds the cranes in serial production, customising them as required: “We look at what vessels and cargo the customer will be receiving. We have a production plan, based on our experience of the market. For each crane, production takes eight months. If we didn’t start production until orders were in, we couldn’t offer the three months’ lead time that we do. We judge demand in advance, and build to meet this. This occasionally means that unordered cranes are left on the test bed for a while, but ensures short lead times for customers.”
Liebherr has also launched a new crane over the last year, the LHM 600. As Bachmann explains, the differences between the first two units sold illustrate how these cranes can be tailored to different customer’s needs: “we’ve sold two units, one to Korea and one to Spain. The Korean crane was designed for heavy lift operations, and makes use of the full 208t capacity. The Spanish crane will be used for bulk handling. It has two 72t winches, giving it less capacity, but much faster operation.”
The advanced order system used by both companies means that cranes can be delivered with a relatively short lead time. Bachmann says, “The lead time for HMCs is three to four months, while for gantries it is eight to twelve months. Additionally, for gantries a port operator will have to invest in infrastructure changes, while for HMCs, you can start work as soon as the crane is delivered, so long as the ground pressure is OK.” This short lead time, and their ability to be deployed anywhere, without building new rails or other quays, mean they can be used to expand port capacity quickly to meet new demand. Despite weighing 540t overall, the LHM 600 only exerts a uniformly distributed load of 1.6t/sq m upon the quay, and a maximum load of 6t per tyre. Liebherr says that even this can be improved upon where needed, by adapting pad size, the supporting base and the number of axle sets.
AB Ports’ Schofield says, “I feel there is little to choose between the major suppliers of MHCs. We have had an equally good experience with both Liebherr and Gottwald. However, rather than comparing technical features of each machine, we tend to be influenced by the overall ‘cost of ownership’ of MHCs. We focus particularly on our own experience in terms of reliability and maintainability in specific types of operation, coupled with the quality of product support provided by the manufacturer.”
