coppercapped
Established Member
A couple of observations...
Only the very recent diesel rail vehicles meet the exhaust emissions requirements of the Euro V (Off-road vehicles) standard. Therefore it is hardly surprising that places like Salisbury and New Street (to take two examples at random) reek a bit when Class 158s or Voyagers are around. This generalisation can be extended to cover the bulk of the UK diesel rolling stock fleet.
That traces of exhaust gases make their way into the interior of rail vehicles is hardly unexpected since, unlike road vehicles (except in heavy traffic) with the exhaust at the rear, the exhaust of the vehicle in front can't be more than 20-odd meters away from the air intake of the following vehicle. In general rail vehicles exhaust at roof level for obvious reasons and air intakes also tend, at least these days, to be on the roof. The HST intakes were under the sole bar which avoided the exhaust ingestion issue — but then people bitched about the smell of the brakes.
Older vehicles, such as the Modernisation Plan DMUs and locomotives, had fuel injection systems that were nowhere near as effective in metering fuel to the cylinders as more modern ones. Coupled with opening drop-lights to every door it is clear that the exhaust will get inside. Today that may be seen as unacceptable - but, believe me, it was a lot, lot better than being continually bombarded with smuts and smoke from steam locomotives.
Don't make the common mistake of judging the past with todays standards and preconceptions.
Only the very recent diesel rail vehicles meet the exhaust emissions requirements of the Euro V (Off-road vehicles) standard. Therefore it is hardly surprising that places like Salisbury and New Street (to take two examples at random) reek a bit when Class 158s or Voyagers are around. This generalisation can be extended to cover the bulk of the UK diesel rolling stock fleet.
That traces of exhaust gases make their way into the interior of rail vehicles is hardly unexpected since, unlike road vehicles (except in heavy traffic) with the exhaust at the rear, the exhaust of the vehicle in front can't be more than 20-odd meters away from the air intake of the following vehicle. In general rail vehicles exhaust at roof level for obvious reasons and air intakes also tend, at least these days, to be on the roof. The HST intakes were under the sole bar which avoided the exhaust ingestion issue — but then people bitched about the smell of the brakes.
Older vehicles, such as the Modernisation Plan DMUs and locomotives, had fuel injection systems that were nowhere near as effective in metering fuel to the cylinders as more modern ones. Coupled with opening drop-lights to every door it is clear that the exhaust will get inside. Today that may be seen as unacceptable - but, believe me, it was a lot, lot better than being continually bombarded with smuts and smoke from steam locomotives.
Don't make the common mistake of judging the past with todays standards and preconceptions.