Tunnels: Canal de St-Quentin

Tunnel de Tronquoy (1,098 metres)

This tunnel is near Lehaucourt in the Aisne département (02), France.

The brick lined tunnel is one-way only and controlled by traffic lights. It is 1,098 metres long with a minimum width of 6.75 metres and a minimum air draught of 3.58 metres. It is lit throughout and has a towpath on one side only.

The 92.5 kilometre long canal de Saint-Quentin is one of several canals that link between central France and the industrial north. It connects the canalised river Escaut at Cambrai to the Canal latéral à l’Oise at Chauny.

This tunnel is on the canal's summit at an altitude of 83 metres.

South east portal

North west portal

Tunnel de Riqueval (5,670 metres)

This tunnel is near Riqueval in Aisne (02), France.

The brick lined tunnel is one-way only and boats are towed through by an electric tug. It is the longest canal tunnel still in use in France and is 5,670 metres long with a minimum width of 6.75 metres and a minimum air draught of 3.58 metres. It is lit throughout and has a towpath on one side only.

The tunnel was opened by Napoleon I in 1810 and in those days it took seven or eight men 12 to 14 hours to pull boats through by walking on the towpath (there being no room for horses). In 1856 a towing tug was built that was operated by up to eight horses walking on a carousel on the deck. The carousel drove a winch that pulled the towing tug along a cable laid on the canal bed. This scheme only lasted eight years as the horses suffered badly from walking in circles in poor light.

The horse carousel was replaced by a steam tug in 1864 but this proved disastrous in that boaters were seriously poisoned by the fumes in the unventilated tunnel. In 1910 the first electric tug was introduced and this is the method that is still used today, more than 100 years later.

The original electric tug is on display in a museum above the tunnel. In its heyday up to 30 Freycinet barges, each 39 metres long, would be towed through the tunnel by the electric tug. The electricity is supplied through overhead cables like those used for trolley buses.

The 92.5 kilometre long canal de Saint-Quentin is one of several canals that link between central France and the industrial north. It connects the canalised river Escaut at Cambrai to the Canal latéral à l’Oise at Chauny.

This tunnel is on the canal's summit at an altitude of 83 metres.