It's a few years ince I travelled by Eurostar, I need to go to Cologne, does anyone know if there is still a smoking carriage. Last time I went to Lyon there was and it was packed.
It's illegal to smoke in any public confined space within the UK, so no train operator can permit smoking on their services within the UK. So there's no way that a Eurostar train could have a smoking carriage. The RailEurope website confirms that smoking is prohibited on all Eurostar services:
http://www.raileurope.fr/corporate/eurostar
Travel from Paris Nord to Koln Hbf would be by a Thalys service. The RailEurope website also states that all Thalys trains are non-smoking:
http://www.raileurope.fr/corporate/Thalys