Information about "Variable Gauge Axles" for overcoming breaks of gauge is a bit hard to come by because different people called by different names. Anyhow, having stumbled upon the "SUW 2000" this has proved most useful.

There are four VGA mostly incompatible systems in Europe plus one each in Korea and Japan.

Existing VGA systems have been around for up to 40 years (Talgo) and perhaps 10 years with SUW, with 5 years of continuous daily practical testing for the latter. VGA offers the prospect of merging the Russian BG zone with the European and Chinese SG zones.

Speaking for the SUW 2000 system, so far the system has between used between SG and a wider gauge, but not for SG and a narrower gauge, where there is less room between the wheels for the VGA stuff and the disc brakes.

Similarly there is not specific mention of the possibility of handling more than two gauges at once, such as BG, SG and NG in Australia. Since the VGA may have holes for the wards of the locking mechanism, particular combinations of gauges may be ruled out.

So far, VGA for locomotives (which also need space between the wheels) is at the toe in the water stage.

So while considerable progress has been made, there is a lot of uncertainty as to what the situation is.

Some of these issues and possibilities have been discussed in the "Benalla-Oaklands Railway" thread.

Comparing VGA instead of Gauge Conversion:

* VGA has cost the advantage if (just wheat) traffic is low and the line is long.
* GC has the cost advantage if traffic of several kinds is higher and the line is short.
* VGA has a disadvantage if custommade VGA bogies are needed with a long delivery time.
* VGA and is gauge orphan branch would probably need to piggy in/out track maintenance machine, which may not be easily fitted with VGA.
* GC on the Oaklands line benefits from long track possessions.
* Dual Gauge or a separate SG line from Dynon to Frankston and Eastern Victoria would on the other hand very difficult.




In the above map, showing the current situation with SUW 2000 VGA, Pakistan is shown SG (red) when it should be BG (blue).

The map also has an inset with a picture of the SUW 2000 Gauge Conversion Track, which is quite small compared to a bogie exchange or transshipment yard.

Note: "For example, spending a few hundred million dollars to upgrade the Melbourne-Sydney-Brisbane rail link to get freight traffic off the Hume Highway and create a standard gauge link from Dandenong to Dynon Road freight terminal to move freight by rail to all the mainland capitals"

Such a link, albeit quite short, perhaps 50km, is through difficult territory and would be expensive. What about a Variable Gauge Axle alternative such as SUW 2000?

In future, the journey time to Berlin could be substantially reduced by using modern trains manufactured by the Spanish company Talgo. In October, Russian Railways and Talgo agreed to study the possibility of using Talgo Trenhotel Series 7 trains equipped with an automatic gauge-switching system on the Moscow — Berlin route. Specialists are now working on a joint feasibility study for the project. In parallel, three Spanish-made passenger carriages will be trailed at a testing facility in the town of Scherbinka. If successful, Russian Railways may purchase at least three Talgo trains for use on the Moscow — Berlin line.

See: http://www.railpage.com.au/f-t11346907.htm

I don't think there is much demand for conversion between narrow and standard gauges as the through traffic between regional WA and regional Qld to and from the national network is fairly small.  

The broad/standard conversion has more prospects in Victoria and SA.  However, the cost of having special facilitities for relatively few freight trains strikes me as a bit extravagent as a lot of gauge conversion can be integrated with much needed upgrading for a one off cost.

Passenger trains, of course, don't need gauge conversion.

I don't think there is much demand for conversion between narrow and standard gauges as the through traffic between regional WA and regional Qld to and from the national network is fairly small.  

The broad/standard conversion has more prospects in Victoria and SA.  However, the cost of having special facilities for relatively few freight trains strikes me as a bit extravagent as a lot of gauge conversion can be integrated with much needed upgrading for a one off cost.

Passenger trains, of course, don't need gauge conversion.

I agree that traffic from regional WA to QLD is small, a few envelopes with 55c a stamp thereon.




However, during droughts in WA and bumper harvests in Qld, and visa versa it would be useful to transfer rolling stock to where it is needed.

The Inland Railway would also save costs if it could connect to narrow gauge Queensland in the short term with out having to gauge convert all the relevant tracks.

Similarly, the ability to change the gauge of rolling stock quickly would facilitate the gradual conversion of country Vic, even though the non-convertible concrete sleepers on the RFR has otherwise block this possibility.

With the Vic passenger fleet split into separate BG and SG parts, each requiring their own spares. With AGW, the spares could be common and you would need fewer of them, which helps defer to cost of the AGW. It then becomes an issue which is more expensive, the carriages or the wheelsets.

And so on and so on. Remember that gauge change wheelsets are not exactly new, having being around for 40 years.

One brand of changeable wheelset might cost 115000 Lithuania LTL or about 63000 AUD per bogie in 2007. The gauge changing track are small. perhaps 20m long by 8m wide, and can moved around if more that one gauge changing system is in use. The makers of these things do not appear to be much interested in selling them giving the paucity of practical information that they make available.

Jeez you're drawing a long bow!

It's cheaper and easier to gauge convert rollingstock as required between narrow, standard and broad gauge bogies.

It already happens in your drought/bumper crop scenario.

You'd pay more for two gauge convertable bogies than you would for a whole new or second hand non-gauge convertable wagon!

You're going to waste your money if you think these axles are your answer. They're perfectly suited to light axle load trains that gauge convert often, not heavy axle load goods wagons that gauge convert once every several years.

M