On Sun, 15 Dec 2019 15:23:27 +0000, David Higton wrote:

> In message 
>           Martin Gregorie  wrote:
>
>> now that diesel smoke has mostly disappeared.
>
s'true - it seemed that, back in the '70 or '80s, no bus or truck could
move off without emitting a gout of black smoke from its exhaust. I was
never sure whether it was better to have it belching straight up from
vertical pipes or to sweep it across the road from a side- or rear-facing
exhaust. London taxis laid pretty good smoke screens too.

But other places were worse. Much worse. I can still clearly remember the
experience of following a row of 'well-maintained' Indian trucks through
the single way tunnel into Kashmir. Even on full beams you could barely
see the back of the truck 5-10m in front of you. Ventilation was entirely
due to the movement of trucks pushing air through the tunnel.


--
Martin    | martin at
Gregorie  | gregorie dot org

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