Cranes designed to run on commercial railways comprise a specialised sector of the industry where volumes are limited and the life expectancy of the product is long. However, with many countries once again investing in their over-neglected railways, there is considerable activity, particularly in the market for small railway cranes.
Because volumes are low railway plant is often designed to be versatile, to operate as an excavator as well as a crane for example, to enable plant hire companies to maximise their use and get a better return on the investment.
There are several factors peculiar to railway working such as the ability to operate under the catenary, or overhead power pickup system. Larger models, in particular, must be able to handle loads with the boom in a horizontal position. However, some recovery cranes are too large to work under the catenary system so sometimes must be dismantled to gain access to the jobsite. Road/rail models that have tyres for road use and separate wheels for running on rails can be useful here in reducing the amount of dismantling necessary. Lessening the time that a track needs to be occupied by a crane and thereby precluding use for normal service is an additional advantage. For similar reasons the ability to work on multiple tracks without tailswing intruding into adjoining line space is also important.
The longevity of the plant can lead to problems for maintenance and overhaul in that parts may be unavailable for very old but otherwise still useful models.
Laying track and building bridges
Mannesmann Dematic Gottwald offers a comprehensive range of rail mounted cranes with both telescopic and fixed jibs. A basic modular system of components such as standard rolling stock parts means many different configurations are available. The track laying and bridge building cranes range in capacity from 20t up to 150t. Some models can lift and transport complete track panels and points with the boom in the horizontal position. This allows safe working under the catenary.
Launched in response to customer demands for more speed, capacity and safety, the model GS 150.14 TR is the latest track maintenance crane from MDC-Gottwald. It can travel at up to 100km/h under its own power and can be towed in a train at 120km/h to minimise travel time. The TR suffix stands for Telescopic Reversible which means that the boom can be telescoped in or out of either end of the crane. Working direction can be changed without having to slew the superstructure which allows operation in restricted areas such as tunnels and near signalling, walls etc. Zero tail radius means there is no counterweight to obstruct trains on adjacent tracks when the crane is operating to one side. Working underneath the catenary, maximum outreach beyond the coupling is 20m and lifting capacity is 37.5t.
Good capacity when lifting to the side free on wheels is particularly important in railway applications. To this end the crane’s superstructure can be offset by 500mm to give a higher balancing load moment. MDC-Gottwald says that the outrigger plates are large enough to not need mats or sleepers under them which saves time. The GS 80.24 TR can be operated with only one outrigger set, which the company claims is a unique feature. There is also less chance of setting outriggers on the ends of track sleepers which risks breaking them off.
Most models run on rail only but the AC 50R is a road/rail version of Mannesmann Dematic’s three axle Demag mobile crane. It can travel at up to 25km/h on rails and the bogies have hydraulic traction and braking rather than what are effectively just guide wheels on other designs. This means that the crane can cope with steeper gradients and it can be used for towing.
Two AC 50R models have recently been delivered to a private contractor in Japan for rail maintenance work in Tokyo. Other recent deliveries include two 200t cranes to the Korean National Railroad and eight 140t capacity units to Indian Railways.
The first unit in an order for four new Cowans Sheldon diesel hydraulic breakdown cranes is due for delivery about now to Indian Railways and the remainder will go later in the year. The cranes can lift 140t at a 9m radius. Now part of Rolls Royce, Cowans Sheldon cranes have been used by Indian Railways for more than 160 years. Indian Railways now has about 100 units in service on its 40,000km long, 1676mm gauge network.
Iowa Mold Tooling (IMT) of the USA has more than 20 years experience manufacturing telescoping, articulating and special purpose cranes for railway applications. Versatility is the key to their success, according to the company. Telescopic models IMT 1014, 2015 and 3816, for general rail applications, are said by IMT to sell on longevity and quality.
Operator demands
The articulating material handling crane model 8000L is specifically designed for rail applications and incorporates features demanded by operators in the rail industry. These include holding valves on the lift cylinders and the ability to operate several functions simultaneously.
Rated at 7tm, the multi-purpose 5200R is used on gang trucks for rail and tie repair. In production for four years, it has 450o rotation and the version with two hydraulic extensions has a horizontal reach of 8m. Fitted with an optional manual extension, maximum horizontal reach is 9.8m where it can lift 545kg.
Another US company, SpanDeck, began manufacturing rail cranes eight years ago with the 130t capacity model 26011. In its latest form, the Mantis-branded 30011 has several improvements over the first model. Lifting capacity is now 134t (150 US ton) at 3.3m radius. It also has an 11t self-erecting counterweight to give more capacity at extended radius.
A cold weather package, emergency hydraulic system and lights for night working are all fitted. There is a 20t-capacity deck winch for recovery work and a 45t capacity boom extension.
The crane is truck mounted and has road/rail capability. In remote areas, particularly in Canada, it sometimes has to travel up to 65km by rail from the nearest road access point. By road it can travel at up to 105km/h. Maximum speed by rail is 48km/h which keeps track occupation time to a minimum.
Freightliner, owned by Mercedes-Benz makes the crane carrier which means service and parts are available worldwide. Power comes from a 400hp Detroit Series 60 diesel and drive is through an Allison 755 DR transmission and two speed rear axles.
Railway customers in North America include Union Pacific, BNSF and CN. SpanDeck says that most years it has about 75% of the US market and it already has three units in production for 1999 which is likely to be the annual total.
Far higher volumes are involved for UK-based Rexquote but the product is rather different. The company specialises in adapting plant such as excavators, access platforms and dumpers for operation on road or rail. Claiming as much as 90% of the UK market, Rexquote has recently developed a new excavator-based model specifically for lifting.
Described by managing director Steve Morris as “a crane that can also be used as an excavator”, the Rexquote Super Railer is based on a 16t wheeled excavator but modifications involve much more than just adding a set of rail wheels. The engine and major hydraulics are relocated forward, which, combined with a new counterweight, typically reduces the all important tail swing by 600mm. Lead is used in the new counterweight and is also added in the bogies to lower the centre of gravity.
The Super Railer is up to 6t heavier than the Road Railer (intended more for excavator work). A Prolec LW4-R safe load indicator is fitted to comply with standards for rail use. The specially fabricated boom allows working under wires but a load can also be lifted to a height of 10m.
Rules and regulations
Also in the UK, IHI dealer AGD has carried out a feasibility study on the adaptation of the IHI CCH50T mini crane to rail mounting. Interpretation of the regulations rather than engineering problems is the major hurdle according to the company. Its research suggests that it is “far easier to rail mount excavators to be used as cranes than it is to produce a specialist rail mounted crane”. Despite this the company is continuing with its aim to provide a self propelled rail crane. In addition to the mini crane for rail work, AGD has used the larger CCH300T for bridge rebuilding on the remote Carlisle to Settle line in the north of England.
Regulations might have been less of a problem in Denmark where Danish Railways (DSB) was a joint developer of the 140 DSB, otherwise known as the Truck. Because the railway signalling system prevents trains using lines already occupied by other trains, the Truck has to be able to reach jobsites by road. The unit is comprised of an Effer model 140N3S loader crane mounted on a Scania 8×4 chassis that has been adapted for either road or rail operation. Two variable speed hydraulic pumps supply the driven rail wheels and the crane functions.
Maximum lifting capacity is more than 27t and is still 14t at the maximum 9m outreach, according to Effer. The company also says that the knuckle-boom design allows operation without having to remove the catenary. A safety device prevents the boom coming into contact with overhead power lines.
High tensile steel construction keeps gross vehicle weight under 32t so there are no special speed restrictions for road travel. Positioning on rails involves setting the stabilisers and then side shifting the truck by up to 2.7m over the tracks. Dimensions and certain features are such that the crane can be used in the new Storebaelt tunnel.
Development took Effer Engineering more than eight months. The Danish railway operator has had one unit since last February and a second is now due for delivery.
