All of you together answer the question as to why there is justification to enlarge the British loading gauge to accommodate 9ft 6in high boxes on 'standard' wagons, when wagons with small wheels exist, but I thought I'd join in anyway.
It's true, that although small wheel wagon designs exist, the 'Low-Liner' units in use with Freightliner being the prime examples, it's almost certain that in comparison to 'standard' 60ft platforms, these wagons:
1. Cost more to maintain
2. Incur higher track access charges
3. Impose more restrictive payload conditions
4. Are more expensive to rent/buy
An important thing to bear in mind I think is that the port operators of Southampton and Felixstowe must not have genuine cause for concern that 'the other' port has an inland transport advantage over 'their port'. At the moment, in intermodal terms, Felixstowe has a real advantage - Freightliner can, in theory, from Felixstowe form a 750m train made up entirely of 60ft flat wagons, where as those trains from Southampton have to include either the Finnish pocket wagons and/or the low-liner wagons to transport the 9ft 6in boxes. So therefore, the Southampton trains are of a lower capacity.
This means on competition grounds alone, there is reason to upgrade the Southampton route to a larger loading gauge.
But the issue of the loading gauge is not one that relates just to the height of shipping containers, which indeed will, as time goes on, consist more and more of 9ft 6in high boxes.
The loading gauge is also relates to the length of containers.
For example, observers of Freightliner trains from Felixstowe - a port already benefiting from a 9ft 6in-cleared route via London - will see that every so often there will be, sitting aboard on a 60ft wagon, a Maersk-owned 45ft-long, 9ft 6in high container, normally a reefer unit.
Now admittedly these particular 45ft containers are not in fact road-legal in the UK/EU, due to issue of their corner castings and the EU regulations relating to HGV turning circles, and so they remain 'special cases'. But one has to expect that one day, the 45ft deep-sea containers will be of a similar design to the EU-friendly 45ft designs that already exist, serving the internal EU trade.
Operators of these EU-friendly designs include Ge-eX, for example. See:
www.ge-ex.com.
In other words, the 40ft pocket wagons and low-liner wagons are clearly also of no help when it comes to carrying 45ft boxes, and this is another reason why the route from Southampton needs to be made as flexible as that from Felixstowe.
By the way, the Megafret and Multifret wagon designs are not officially small-wheeled wagons. Although they employ wheels that are smaller in diameter to those on 'standard' 60ft platforms, they are not so small as to make them undesirable from a infrastructure viewpoint. The French authorities, for example, would not allow them to run over French metals if they were - in fact, both the Megrafret and Multifret wagons are actually French designs and they first ran in France!
But of course, the platform heights of the Megafret and Multifret wagons are too low to cater for 9ft 6in traffic from Southampton. In addition, they cannot carry the heaviest of containers, and they clearly are not as 'space-efficient' in comparison to 60ft units, at least when it comes to 20ft/40ft deep sea trade.
Oddly enough, just as Network Rail steams ahead with both the Southmapton upgrade and the Nuneaton upgrade, WH Davis comes out with a wagon design that solves just about all these problems. See:
www.whdavis.co.uk.
The 'Super-Low' design of wagon that WH Davis has built can carry 45ft high-cube units, within an unmodified loading gauge, while employing wheels that are not too small as to make a civil-engineer responsible for track maintenance scream.
It remains to be seen how much these wagons will cost to buy or rent, but if they had come out about ten years ago, you may well have seen Freightliner investing in a fleet of these instead of having to remain dependent on the classic 60ft wagon design. This would have possibly meant that Network Rail would have not felt any pressure to commit to any loading gauge upgrades.
With this in mind, I would imagine that because of the arrival of the WH Davis design, we are not going to see Network Rail quickly agree to upgrading the loading gauges that connect to the other container ports in the UK, such as Teesport. I would expect that Network Rail will argue that any intermodal operator wishing to serve Teesport, and any other port like it, ought to invest in the WH Davis wagons to serve them.
While this option may be less desrable from viewpoint of the port owners themselves, it is true that in the case of Teesport, most of the existing trade is already 45ft traffic - both 9ft-high and 9ft 6in-high in nature - because the port caters for intra-European trade. So the WH Davis design is actually a more efficient option for this traffic than the classic 60ft design.
Yes, Teesport plans to open a deep-sea container terminal, which means it will in the future handle more containers that are 20ft or 40ft in length, but the chances are that intermodal operators will wish to run trains that will be a mix of this 'new' traffic and the European traffic, so again, this favours the WH Davis wagon design.
In summary, it's all good.
Which ever way you look at it, Britain is on the up-and-up when it comes to intermodal road-rail transport. The only question-mark area remains the transport of standard 4m-high piggyback trailers, but that's another story.
