Since the 'Guillaume Tell' became the first mechanically propelled vessel on Lake Geneva in 1823, the load capacity, displacement and size of the vessels that operate here have increased regularly. At the same time, the motive power of the steam engines also increased in step with advances made in this area.
Maximum size and capacity were achieved at the beginning of the 20th Century ('La Suisse', 70 metres, 1,500 passengers). The required power was an indicated 1400 hp.
Heating was provided by coal. Particular ports - Lausanne, Geneva and Le Bouveret - therefore had to be supplied with coal, which was extremely heavy work. All crew members had to help carry the coal on their backs. While the vessel was under way, teams of stokers fed the furnaces using shovels.
With regard to comfort, the vessels were originally "bare deck", with only movable, and later fixed, tents to protect the passengers. Later came the "demi-salons" ('Winkelried II', 1871), areas offering greater comfort at the stern of the vessel, and finally the twin-deck saloon ship ('Mont-Blanc II', 1875).
Alternatives to steam propulsion became available on the following dates:
- 1905, the 'Venoge', a screw-propelled sightseeing boat driven by a diesel engine. This was the first boat to be fitted with a Sulzer diesel engine. This boat is still in service.
- 1935, 'Genève', conversion of steam propulsion to diesel electric propulsion (a diesel engine drives a generator which in turn drives two electric engines that power the paddle wheels via a reducing gear). This vessel can still be seen at anchor in Geneva.
- 1960, 'Col-Vert', the first screw-propelled, diesel-engined passenger vessel ordered by CGN. This boat is still in service.
The steam ships were originally built in various locations, but later only in Switzerland (Escher Wyss until 1892 (Major Davel)) and then by Sulzer Frères alone until the last steam ship, 'Le Rhône II', was ordered in 1927.
At the turn of the 20th century, the general architecture of the boats was practically fixed. There was an "Escher Wyss style" and a "Sulzer style". The operator specified the desired capacity, the degree of luxury of the interior fittings and the required speed.
The very interesting history of the development of steam propulsion is a story in itself in technical terms. The first engines used were single-cylinder, rocker-arm units fed by very low-pressure boilers.
These were followed by:
- Low-pressure oscillating cylinder units, with higher-pressure units later.
- Oscillating cylinder units using the Woolf system.
- Compounding fixed-cylinder units (double expansion, steam).
- The "classic" units, with superheated steam, as can still be seen today. These can be broken down into oblique axis, compound superheated steam, and Gooch distribution system.
Boating on Lake Geneva in the 21 st century It is certain that, if it had not been for conversion from coal firing to oil firing (heavy oil originally, now light oil), there would no longer be any steam ships in service today.
CGN continues to run five steam ships: three with "classic" systems as described above and two with individual systems.
The 'Rhône' (1927), as a final attempt at modernisation, has a compound system with single-seat (Diesel type) valves to distribute the steam, which are driven by oil-pressure-operated servomotors. The engineers operate the units with a single lever, and a central lubrication system distributes the oil to the required points. For this reason, the crankshaft cranks are covered with a lid.
The 'Montreux' (1904), originally steam-driven but later converted to diesel electric (1962), was fully restored and fitted with a new steam unit in 2001: oblique axis, simple expansion in two equal cylinders, highly superheated, with a Joy distribution system.
The boiler operates automatically and supplies superheated steam at 340°C and 17 bar. The system is designed to be operated by a single engineer.