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Re-engineering Rail Freight

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Unlike most passenger train operators, rail freight must operate at a profit since it gets no government support. As it works to tight financial margins, it is difficult to justify large capital investment without a guaranteed market.

In such an environment, it is difficult to fund expensive, innovative rolling stock. Yet, our ‘Unlocking innovation online’ feature in the previous issue of Rail Engineer showed how the Rail Operations Group (ROG) was bucking this trend by investing in Class 769 bi-mode units as well as developing the Class 93 tri-mode locomotive concept.

ROG was formed in 2015 and currently specialises in the ad-hoc movement of rolling stock. At that time, thousands of new rail vehicles were about to be delivered. Moving these new trains from ports and factories to their depots was a significant market opportunity. To move this high-value kit without delay, ROG acquired various locomotives and equipped them with a range of coupler types. It also focused on the train planning needed to make these moves at short notice.

An early ROG innovation in 2016 was the fitment of miniaturised electrical brake translation equipment to their locomotives. This enabled the varying pressure in the locomotive’s brake pipe to control the electric brakes on the new trains they are towing. Previously, this translation equipment was contained within translator vehicles which were difficult to obtain. As a result, in some cases, new trains were dragged unbraked with a braked barrier vehicle at the rear, fed by a very long air pipe that ran through the train from the locomotive. This presented significant planning problems, as such trains were limited to 45mph and there were not many barrier vehicles to be had.

Class 57 locomotive acquired by ROG in October 2018. It is fitted with brake translation equipment and Dellner 12 couplers.

With new train procurement in the UK being done on a ‘boom and bust’ basis, the requirement for new train moves, and the associated movement of displaced stock, will be much reduced in a few years’ time. ROG is therefore looking to its future, for which it has developed two innovative concepts.

High speed logistics

The internet-driven increase in e-commerce has resulted in a 20 per cent increase in road van use over the past ten years. The five billion packages that are delivered in the UK each year make the express delivery market worth £17 billion. ROG and its sister company, Orion, believe that rail can capture a share of this market and that the required investment to do so would only require rail to take a small percentage share.

As a result, Orion is developing a rail logistics network that will consist of around twenty stations and twelve ports or logistics terminals. These will be linked by trains offering unbeatable journey times. For example, Origin envisages a 5.5-hour journey time between London and Glasgow, compared with about ten hours for a lorry trip. The use of city-centre stations further increases the attractiveness of this service.

Proposed ROG highspeed logistics network.
Class 769 engine raft.
Class 93 locomotive.

To date, rail has not been able to provide such a service due to the lack of suitable rolling stock. Most UK rail freight is containerised intermodal cargo, which averages around 30 miles per hour. What is needed is a go-anywhere train that can run at 100mph to passenger timings.

The Class 769 tri-mode units that have been developed by Porterbrook (issue 168, October 2018) meet this requirement. These are converted surplus four-car Class 319 units that originally ran on the Thameslink route and so were powered by either 25kV AC OLE or 750V DC third rail. The conversion adds a 390kW diesel alternator set to each of the two trailer coaches, driving the traction motors via the existing DC bus line. After losses, and the requirement to power auxiliary equipment, are considered, this gives the unit 550 kW of diesel power at the wheels. Although this is little more than half the unit’s electric traction power, it is sufficient to give the unit a balancing speed of 87mph on a level gradient.

As such go-anywhere units are ideal for the proposed high-speed logistic service, ROG has ordered five Class 769s. ROG is also interested in acquiring Class 319 units which, with minor modifications to control circuitry, could work in multiple with the Class 769s. Karl envisages running a 12-car train with two Class 319 units and a single Class 769 unit. Such a train would run on electrified lines for most of its journey and use the Class 769 as a tractor unit off the wires, when it would run at a slow speed, say 40 or 50mph, for a short distance to its destination.

Two types of conversion are required before ROG can start its logistics service: Wabtec is converting the Class 319 units to Class 769 units and both types of units need to be repurposed to enable them to carry packages and light freight. The specification for this repurposing has yet to be finalised and will take account of the opinions of prospective customers. As part of this exercise, a unit is being fitted with various types of floor (roller, vinyl and a strengthened floor).

It had been expected that ROG would receive its first Class 769 unit in September. However, due to delays, it is now expected that the first unit will be delivered around the end of the year. This should enable a pilot service between London Gateway and Liverpool Street station to be introduced early in 2021, with the full logistics service launched a year later.

Orion’s delivery service will be supported by digital logistics technologies that will provide state-of-the-art customer service, such as real-time tracking. Various options are being considered for last-mile deliveries from city-centre stations, including the use of autonomous vehicles.

High speed freight

ROG also has an innovative vision for loco-hauled freight, as chief executive officer Karl Watts advised Rail Engineer in a recent interview. He felt that, currently, freight operating companies are “glued to Class 66 operations”. Although the Class 66 was designed 25 years ago, it is a reliable machine which does its job well and, with the tight margins associated with rail freight operation, there is little incentive for freight companies to invest in modern locomotives, even though they have lower fuel and maintenance costs.

Yet, looking to the future, Karl believes there is a requirement for an advanced freight locomotive. The decarbonisation agenda requires rail freight to reduce its CO2 emissions. Furthermore, the Class 66’s two-stroke engine fails to meet current particulate emission standards.

Reducing emissions requires a reduction of diesel running under the wires. However, providing an electrically powered freight locomotive that offers acceptable performance off the wires is a challenging requirement.

Another problem with freight traffic is its slow speed. When Freightliners (the wagons, not the company) were introduced in 1965, they ran at a maximum speed of 75mph, which was comparable with the speed of passenger trains of the time. Yet container trains and Class 66 locomotives still run at a 75mph maximum speed today. Pathing freight trains running on a busy rail network, on which passenger trains run at 100 or 125mph, is problematic. The rail network could accommodate more freight if it could run at higher speeds.

Fast rail freight would also support the decarbonisation requirement as a modal shift of freight to rail would reduce overall CO2 emissions. Covid-19 may have reduced rail traffic for now, but, in the future, a high-capacity rail network will have an essential part to play in decarbonising UK transport.

For these reasons, Karl believes that there is a requirement for a fast freight locomotive that is electric-powered under the wires but is self-powered away from them. The Stadler-built Class 88 is such an electro-diesel locomotive and is a development of the Class 68 diesel locomotive. These are operated by Direct Rail Services (DRS), which first acquired them in 2017 and 2014 respectively.

The Class 88 is a Stadler ‘UK-Dual’ locomotive. It has a maximum speed of 100mph and a maximum power of 4,000kW under 25kV AC OLE and 700kW in diesel mode using a Euro IIIB emissions compliant Caterpillar C27 diesel engine. However, its power in diesel mode is only equivalent to that of a single Class 20 locomotive. Hence, for freight away from the wires, the Class 88 is only suitable for ‘last mile’ operations in sidings or slow-speed operation on freight-only branches.

Tri-mode power

Karl explained how ROG has been in discussion with Stadler to develop the Class 93 locomotive, which will have main-line freight capability on non-electrified lines. This a development of the Class 88 locomotive with a more powerful diesel engine, a traction battery and an increased maximum speed of 110mph.

The locomotive is described as a tri-mode as it has three different power sources. However, it only has two modes of operation, electric and diesel/battery hybrid. In electric mode, the batteries are charged when braking or from the transformer. As the batteries use the space occupied by the braking resistors in the Class 88, when the batteries are fully charged, the locomotive has only its friction brake.

In diesel/battery hybrid mode, the batteries are charged both as the train brakes and by the diesel engine when it is not operating under full load. When the train accelerates, the batteries give it the extra power needed to get up to speed. This is a significant benefit as accelerating a freight train of over 1,000 tonnes up to its operating speed can take several minutes.

The Class 93 will have a six-cylinder Caterpillar C32 turbocharged engine, rated at 900kW at 1,800rpm, which meets the EU97/68 stage IIIB emission requirement. It has two Lithium Titanate Oxide liquid-cooled battery packs, which have a rapid charge and discharge rate. These each have a 40kWh capacity with a peak power of 200kW. Thus, whilst the train is accelerating, the Class 93 will have a peak power of 1,300kW for up to ten minutes, which is almost twice that of a Class 88 in diesel mode.

As a result, the 86-tonne Class 93 is capable of hauling 1,500 tonnes on non-electrified routes and 2,500 tonnes on electrified routes. With a route availability (RA) of seven, it can be used on most of the rail network.

Both the Class 88 and Class 93 are Bo-Bo locomotives. DRS’s original intention was that the Class 68 should be a Co-Co locomotive, as the Class 66 is. However, Stadler convinced DRS that modern traction electronic control would enable a four-axle locomotive to haul a heavy freight train and was able to demonstrate that this was the case on the Velim test track.

With its ROG pedigree, it is not surprising that the Class 93 is also designed to haul passenger stock. For this, it has a variable height Dellner coupler and a three-step Westcode brake, in addition to its conventional two-pipe air brake.

Phenomenal benefits

Modelling the performance of a Class 93 locomotive has shown that it offers “phenomenal” business benefits. For example, the running time of a 1,500-tonne freight train between Felixstowe and Mossend of 11 hours 9 minutes with a Class 66 locomotive would be reduced to 8 hours 32 minutes using a Class 93. Such reductions in running time offer significant improvements in freight train utilisation. A further example is that a class 93 would enable a train to make two return trips a day between Thames Gateway and Corby.

The Class 93 also offers significant reduction in operating costs. As well as lower maintenance costs, it has a third of the fuel consumption of a Class 66. Furthermore, the 86-tonne Class 93 has lower track charges than the 130-tonne class 66.

Karl considers that the Class 93 will be a true go-anyway mixed-traffic locomotive, with the ability to haul fast passenger trains and freight trains of up to 2,500 tonnes on fully electrified routes. Moreover, he considers that it could change the business paradigm of intermodal rail freight operations in which the commercial incentive is to maximise income by increasing train length, even though this increases running times.

He believes that the Class 93 could offer a more dynamic operation for modal freight, with an increased frequency of shorter trains running at higher speeds. This would also require faster container flats, for which ROG are also in discussions with various bodies to develop a high-speed freight bogie. In addition to being a more commercially attractive operating model, this would enable more freight trains to be run on a busy railway.

Clearly, ROG is an innovative company, particularly in respect of its Class 93 concept. It is always good to see railway engineering that delivers business benefits, and this is particularly true with the Class 93, which has the potential to revolutionise intermodal rail freight.

However, at a cost of around £4 million per locomotive, a Class 93 fleet requires a significant investment to realise these benefits. Perhaps for this reason, an order has yet to be placed for Class 93 production, even though the concept was first proposed in 2018. Although borrowing £10s of millions is far from straightforward, given its benefits, it is to be hoped that an order for the Class 93 can be placed soon, and Rail Engineer looks forward to seeing the first one in operation.


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