WHERE IS HEAVY HAUL HEADED?

Introduction

Heavy haul is a relatively recent outgrowth of two centuries of railways. The first heavy haul article appeared in 1972¹ ; the first heavy haul conference took place in 1978. Despite its youth, the heavy haul industry has acquired distinct identity and competent reputation. Thirty years on, one may formulate research questions to examine how the industry has shaped up, what distinctive competencies support it, whether its understanding has broader application, and where is it headed.

An approach

First research questions might be prompted by subliminal perceptions that heavy haul of bulk commodities, such as coal, grain and iron-ore, might have reached a plateau. Using content analysis of trade press articles, as well as conference programs and proceedings, one may extract views expressed by opinion formers. Application of pattern recognition yielded the following sentiments from that chorus of voices.

On the one hand, yes, there are opinions that heavy haul rail is on a plateau. It has traditionally served bulk commodity movements: Nowadays there are examples of heavy haul technology diversifying into relatively short haulage of other heavy traffic, such as chemicals, thereby consolidating its position as freight rail anchor. The 1997 International Heavy Haul Association Conference theme was the only explicitly strategic one. Recent research suggests dominance of arcane issues over strategic direction.
On the other hand, there is strong new clamour to extend freight rail’s distinctive competencies outside the traditional heavy haul context. Particularly in Europe, speakers and writers covet new solutions to rail’s declining freight market share. They demand dedicated freight railway routes with diesel traction, carrying 30 tonnes/axle at relatively low speed, with safety standards appropriate to freight traffic: The New Opera Project² has potential to trigger a seismic shift in European rail freight outcomes. Clearly this is heavy haul territory.

Railway heavy freight characteristics

The rail transport mode possesses a single-degree-of-freedom-of-translation, constraining vehicles to move back and forth on their guideway or track: That constraint attracts many disadvantages, but important countervailing advantages nevertheless render it intensely competitive in particular market segments. Three underlying, or genetic, technologies—Bearing, Guiding, and Coupling—make a railway a railway, distinct from any other transport mode. Bearing is the ability to carry very heavy axle loads: It utilizes infrastructure- and vehicle structures efficiently, because loads are applied and borne at precisely defined locations. Guiding is the ability to steer wheelsets: It minimizes rail- and wheel life-cycle costs under heavy loads, and supports speeds much higher than unguided surface transport. In heavy haul railways, Bearing and Guiding are often regarded as one technology, but the distinction between them supports deeper insight. Cross-breaking low- and high axle load, and low- and high speed, yields four segments—Heavy Haul (bulk commodities), High-speed Intercity (long-haul passenger), Heavy Intermodal (double-stack containers) and Urban Rail (short-haul passenger). For all four segments, Coupling leverages Bearing and Guiding, to create capacity: It distinguishes the rail mode, which deploys trains of vehicles, from other transport modes, which deploy single vehicles.

The Heavy Haul and High-speed Intercity segments took dominant competitive positions by exploiting just one high attribute—respectively high axle load and high speed. Noting similarities with Heavy Haul, double-stack container trains are the archetype of Heavy Intermodal: There are nevertheless differences, Heavy Intermodal having entered the high speed domain with authorized maximum train speed some 50% higher than Heavy Haul.
One essential distinction of each segment is a dedicated route network. Heavy freight railways are defined by a network that accommodates heavy axle load and, in the case of Heavy Intermodal, are defined in addition by a network that has been cleared for a large vehicle profile. Whatever the justification, a dedicated network focuses attention on the designated task, avoiding distraction from the myriad diversions that beset general freight railways, or monolithic freight-and-passenger railways. However, in respect of freight railways, it is important to note that one significant driver, Competition, can act in opposing directions. Heavy Haul railways are exposed to source competition, typically among countries: A short haul distance therefore leverages competitive advantage. Heavy intermodal railways are exposed to modal competition, among competing modes, typically maritime and/or road: A long haul distance therefore leverages competitive advantage.

Railway heavy freight opportunities

Heavy Intermodal railway traffic originated in the United States, where containers stacked two-high on wagons exploited rail’s high axle load advantage, and progressively spread throughout North America. Starting small, it generated positive cash flow by exploiting available marginal capacity. Today, its contribution to Class 1 revenue justifies new investment in dedicated capacity and terminals. In further exploiting the competitive strengths that the railway genetic technologies impart, most global freight railway growth must lie in the Heavy Intermodal segment capturing traffic from other modes. Already it has spread to Australia, to China (and that on electrified track), and Saudi Arabia is set to follow soon. Currently, Heavy Intermodal applications outside North America are fragmented, but being competitive at haul distances in the range 3000km (against road) to 12000km (against maritime), one may predict that few markets in the Northern Hemisphere will not ultimately be connected by Heavy Intermodal rail links.
Container traffic on the Asia-Europe land bridge is growing exponentially, currently at some 70% per year on the Trans-Siberian Railway. With Kazakhstan and Turkmenistan building a standard gauge railway line, to link the Chinese standard gauge network to the eastern extremity of the European standard gauge network in Iran, the stage is being set for parallel competition among railways in Asia and Europe, as in North America. This will drive investment as the northern- and southern Eurasian corridors vie for container traffic, and one may expect double stacking to follow in due course. Around 35000 route kilometers in North America have been cleared for double-stack container trains. The potential for such traffic in the combined Asian- and European continents appears to be around 65000 route kilometers, representing significant opportunity for application of heavy-axle-load technology.

A suggested research agenda

Double stacking and electric traction will undoubtedly have to co-exist in the Heavy Intermodal railway segment. China Railways have already demonstrated its feasibility. In many instances, electrification will be at 25kV, needing generous clearance. Although perhaps not the ultimate solution for freight railways, the Innorail electrification in Bordeaux city centre makes the point that alternative solutions will be found where overhead catenary proves unacceptable. Rigid conductors are already used at low-vertical-clearance sites. In a 2000 article³, intermittent electrification to combine the advantages of both diesel- and electric traction was proposed: Those advantages could extend to sites where catenary simply would not fit. Railways will have to research these issues, together with the question of physical clearance.
Double stack trains have emerged in settings that do not yet support permissible axle load at North American level, e.g. Australia and China. The 1994 Sperry Award-winning slack free connector for articulated freight cars⁴, elegantly packs lightweight freight into heavy axle load vehicles. Concurrently, some railways have acquired individual double-stack cars with two bogies. From a competitiveness position, less-than-maximum axle load may take the edge off competitiveness, but it nevertheless initiates a sound growth trajectory, with the prospect of upgrading over time. Research is required to inform the trade-off between axle load and competitiveness.
Heavy freight railways require easy gradients, and tolerate tight curves. High-speed intercity railways need wide curves, and tolerate steep gradients. The two requirement sets intersect at wide curves, and easy gradients, frequently a prohibitively expensive solution. This means that heavy freight- and high speed passenger trains seldom intersect, or that each really requires its own dedicated infrastructure. Reconciling high speeds and high axle loads presents a major challenge: Research in Europe in the fields of slab track and wide sleepers is addressing it. Occasionally, nature is benevolent: The forthcoming Saudi Landbridge and -North-South railways envisage fast passenger- and heavy freight trains sharing the same infrastructure in easy terrain. However, the challenge of reconciling good riding qualities with robust track structure remains.
In addition, the challenge of interoperating direct release- and graduated release braking systems is approaching, as railway operations embrace global reach. The Association of American Railroads’ electronically controlled pneumatic braking system will rise to it, if stakeholders can agree on intra-train communications interoperability. The latter question offers scope for research in a field where contending philosophies are still some distance apart.
Conclusions
Historically, many railways were positioned to service common carrier- and social obligations under weak- or regulated competition: The imposition distorted both their markets and their technologies. As railways have been liberated, exploiting markets franchised by their genetic technologies comes naturally. Unsurprisingly, serious new freight railway investment nowadays flows to the Heavy Haul and Heavy Intermodal segments, which fully exploit rail’s genetic technologies. Heavy haul is no longer, dare one say, the technology of North America, plus a few elite railways elsewhere in the world, that total less than 10⁴ kilometers. Rather, it is the strategic future of freight railways, contributing 10⁵ kilometers of robust capacity to global logistics networks. The potentially ten-fold extension of the heavy freight railway domain is where the future of heavy haul lies. It is time for a seismic shift in the task that railways undertake. The prize is a much greater spread of heavy haul, and the railway industry prosperity that goes with it.

¹ Tracks to carry the big mineral hauls. Railway Gazette International, February 1972, pp49-53.
² Vision of a freight revolution. Railway Gazette International, March 2005, p. 115.
³ Editorial, International Railway Journal, February 2000, p. 1
⁴ The Elmer A. Sperry Award for 1994. ASME International Mechanical Engineering Congress and Exposition, November 9, Chicago.


5 June 2005