Belluzzo & The Italian Turbine Locomotives

6 June 2006
The first Belluzzo locomotive was drawn to my attention by Alex Stirrat, who also provided the picture.
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The first turbine locomotive was a small experimental 0-2-2-0T designed by Professor Giuseppe Belluzzo in Italy, in 1907-8. It was a conversion of an old 0-6-0T shunting engine built in 1876, carried out by the Societa Anonima Officine Meccaniche in Milan. One axle was removed, and no less than four turbines were fitted, two on each side. Steam passed through all four in turn before exhausting up the chimney. Steam went first to the front right-hand turbine, and then to the right rear turbine, via a flexible pipe, visible in the picture. The exhaust from that was sent across to the rear left turbine, forward to the front left turbine, and finally exhausted up the chimney through a conventional blastpipe. The turbines are said to have driven the four wheels independently, so presumably the wheels were not fixed to the axles in the usual way.

Left: Belluzzo's quadruple turbine engine of 1907

There is what appears to be a huge steam dome at the rear of the boiler. Whether this was necessary because of the turbine installation is uncertain; no other turbine loco had anything like it.
Since the turbine casings are offset from the axles, there was clearly some sort of reduction gearing involved. This would be essential as turbines spin very much faster than locomotive wheels. There was in fact single stage reduction gearing of 8:1 ratio on the outside of the wheels. All later turbine locomotives used two or three stages of gearing.

The locomotive was a conversion of an 0-6-0 built in 1876; one axle was removed. The 30m2 evaporation surface and boiler pressure of 140psi were retained. (It was 150psi in some accounts)

Left: Side elevation of Belluzzo's 1907 engine.

This drawing confirms that there was only one stage of gearing, on the outside of the wheels. Maximum turbine speed was 2400rpm, which seems rather low, probably as a consequence of the low reduction ratio.

T denotes the actual turbine casings.

Left: Section through the turbine. Moving blades are shown in pink, fixed blades in blue.

In forward operation steam was supplied by duct a and exhausted via b.

Reverse operation was obtained by sending steam backwards through the turbine, supplied by duct c and exhausted via d. Turbines are usually considered to be unidirectional, and I can think of no other attempt to use this method for reversing. The blades had a section of altered profile at the tip end which was used for reverse operation.

This unique locomotive lasted for thirteen years, being dismantled in 1921. Trials would certainly have been run, but if it was put to actual work is unknown. Possibly an inadequate reduction ratio and resulting inefficiency was the downfall of the project, in that ten years elapsed before the next Italian turbine locomotive. No details are currently known of its performance.

Just the the basic facts, please, ma'm...

26 tons
23ft 4in
Heating surface
323 ft2
Boiler pressure
Max turbine speed

Until very recently, I thought no information about this loco could be found, and it is still in very short supply. However here it is...

In 1931, Belluzzo acted as design consultant for a 2-8-2 turbine loco built by the Ernesto Breda company. It had high and low pressure turbines. It is thought to have been tested in the Breda works at Milan, but apparently the Italian State Railway would not allow it to be run on the main line; whether this indicates it was an obvious failure that would only delay traffic when it broke down is uncertain.

Left: The Belluzzo-Breda Turbine Locomotive.

The turbine installation with reduction gearing and jackshaft is in the centre of the driving wheels. The thing that looks like a garden shed on the front is the cooler for the condenser water; the holes in the side are presumably air outlets. The drawings below seem to indicate that exhaust fans were fitted in these side-holes, though they are not visible in this image.

Most of the information in this paragraph is deduced from the engineering drawings below, so accuracy-wise you'd better keep your fingers crossed. The condenser was mounted under the front of the boiler, and its circulating water was cooled by the cooling unit at the very front of the locomotive. The boiler was conventional, with the usual super-heater tubes, and draught was induced by a triple blastpipe. A draught fan, as used in many other turbine locomotives, was explicitly ruled out as these always gave trouble when they were eroded by ashes and cinders in the exhaust gases. This raises the question of the purpose of the condenser, as if it was intended to conserve water, blowing steam up the chimney would not be helpful. (Probably there was a valve that shut off the chimney blast when it was not needed, but so far this is not clear from the engineering drawings below) It is therefore likely that the condenser was instead intended to provide a vacuum for the turbine exhaust, to increase efficiency.

Another design decision was to keep the condenser on the locomotive, rather than put it in the tender, as this avoided large-diameter flexible pipework for the exhaust running between locomotive and tender. The Swiss Zoelly Turbine took a similiar approach, but kept the water cooler on the tender.

One unusual feature of this machine was that it appeared to have two chimneys; one above the cooler (at the left in picture above) and one further back, above the front two axles. In fact the front "chimney" was another air outlet for the water cooler, and was fitted with a fan driven by a small auxiliary turbine. This turbine also drove the condenser circulating pump.

Left: Drawing #1. The front of the Belluzzo-Breda Turbine Locomotive.

On the right is the water cooler A. It looks as if B is the auxiliary turbine. C and C' are the pipes for the condenser cooling water. The thing marked F above the condenser appears to be a feedwater heater, using the auxiliary turbine exhaust.

G is an opening that gives access to the smokebox.

Above: Drawing #2. Vertical section of boiler, smokebox and turbine gearing of the Belluzzo-Breda Turbine Locomotive.

Note the springs making up two stages of flexible drive in the gearing. F is the putative feedwater heater.

Above: Drawing #3. Horizontal section of the Belluzzo-Breda Turbine Locomotive.

The top half of the drawing is a section at the level of the intermediate shafts of the reduction gearing, at A in the vertical section #2 above. The lower part is a section at the level of the jackshaft, at B.
The high-pressure turbine is on the left, with eight nozzle-control valves visible on the top of its casing.

Left: Drawing #4. Two vertical sections through the Belluzzo-Breda Turbine Locomotive.

The left section goes through the centre of the jackshaft. The right section goes through the middle of the blastpipe. See Drawing #2 above.

Left: Drawing #5. Two more vertical sections through the Belluzzo-Breda Turbine Locomotive.

The left section goes through the centre of the fan shaft. The right section goes through ahead of the condenser.

Now the following information is based solely on inspecting the drawings, so exercise caution...

At bottom left a vertical shaft A drives what appears to be a centrifugal pump B, presumably that used to circulate the condenser cooling water. C is the front of the condenser. At the bottom right another vertical shaft D drives the horizontal fore-and-aft crankshaft of piston pump E that is presumably the boiler feed pump. It would be capable of handling hot water, which an injector would not.

H is the auxiliary turbine, driving the transverse fan shaft through what looks like reduction gearing at G.

Left: Drawing #6. Front elevation of the Belluzzo-Breda Turbine Locomotive.

This gives a good view of the vertical water cooler tubes, and the very wide air exhaust "chimney". The brake pump is on the left.

Just the the basic facts, please, ma'm...

47ft 1in

And that's all she wrote. No other information appears to have survived, not even the boiler pressure.


In 1933 the Officine Meccaniche Miani-Silvestri-Grodona-Comi (I think I've got that right) rebuilt a type 685 2-6-2 at Florence for the Italian State Railways. It was built for express service, and was a 2-6-2 with the turbine mounted at the front. No condenser was fitted. It was tested between Florence & Pistoia, (a rail journey I have made myself) but seems to have never been heard of again, which indicates that this design too was unsuccessful. The design maximum speed was 130 km/h but what it was actually capable of is unknown.

Left: The Italian State Railways Turbine Locomotive.

This is the only known photograph; sorry about poor quality.

The turbine and jackshaft of this locomotive is at the front. Forward and reverse turbines built by Schwartzkopff were mounted on the same shaft, with nozzle control by a group of four valves. Early in testing it appears that a turbine bearing seized, causing severe damage to the blading. It was not repaired and trials were abandoned; that was the end of steam-turbine experiments in Italy.

Just the the basic facts please, ma'm...

72 tons
Heating surface
2056 ft2
Boiler pressure
Max turbine speed

Giuseppe Belluzzo was born in Verona in 1876. He taught in Milan and then Rome, and was the author of more than fifty technical books. He was involved in installing turbines in Italian cruisers and battleships.

Regrettably Belluzzo went on to a career in fascist politics; He was elected to Parliament and was Minister of National Economy from 1925 to 1928. No doubt he claimed he had made the trains run on time...
He also, heaven help us, got involved in promoting mythical Nazi flying saucers: see Giuseppe Belluzzo. (external link) You will find that Googling on "Giuseppe Belluzzo" will get you a lot more misinformation on flying saucers than it will information on turbine locomotives; of such is life. I am not responsible for the content of external sites.

Belluzzo died in Rome on May 21st, 1952.

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