In the Australian context, where double-stacking is possible it refers to the process of placing one hi-cube container (9’ 6” or 2.896 m high) on top of another hi-cube container. This requires a low-floor wagon to be used so that the top of the stack is no higher than 6.5 m above the top of the rail.
In Australia payloads are subject to lower axle-load limits and have smaller loading outlines on some routes. Double-stacking capability is now permitted with greater clearance on the Parkes–Adelaide–Perth line/segment. No efforts have been made to enable double-stacking on the North–South corridor where loading clearances are currently restricted to single-stacking of hi-cube containers.
If network capacity is sufficient for double stacking, it is still dependent on availability of low-floor wagons and capacity to change rail yard practices.
Trains with this capability can often carry 30–40% more freight by weight than equivalent single-stacked trains using the same locomotive power. The potential to reduce network traffic may also result in the adoption of more double stacked trains.
Key implementation considerations
Double stacking would require the use of low-floor wagons to convey double stacked containers. Changes to rail yard practices may require additional investment.
Examples of implementation
Introduction of double-stack container train on Indian railway
This study ((Opens in a new window) PDF 27.1 MB) describes the merits of adopting double stacking capability in India. The key benefit of this study is that it provides an example of how the opportunity was identified and assessed in North America and adapted for local conditions (Kumar 2006).
Rail Freight Performance Indicators 2007-2008
This report provides useful context around the key factors influencing rail transit time in Australia. General information and maps are provided to illustrate interstate network constraints, including maximum train height. Statistical analysis of line segments and types of freight is also provided (BITRE 2008).
For the full report on fuel efficiency opportunities in the road and rail sectors, see Fuel for Thought – Identifying potential energy efficiency opportunities in the Australian road and rail sectors (opens in a new window) PDF 1.5 MB.