# The Dark Smoke (Permitted Periods) (Vessels) Regulations, 1958, Schedule

Extent: E+W+S

(1)
(2)
Class of case
Permitted period for emission of dark smoke
1. Emissions from a forced draught oil-fired boiler furnace, or an oil engine.
10 minutes in the aggregate in any period of 2 hours.
2. Emissions from a natural draught oil-fired boiler furnace (except in the cases falling within class 4 below).
10 minutes in the aggregate in any period of 1 hour.
3. Emissions from a coal-fired boiler furnace:—
(a) when the vessel is not under way (except in the cases falling within class 4 below).
10 minutes in the aggregate in any period of 1 hour.
(b) when the vessel is under way
20 minutes in the aggregate in any period of 1 hour.
4. Emissions from a natural draught oil-fired boiler furnace or a coal-fired boiler furnace in the following cases:—
(a) a vessel with funnels shortened for the purpose of navigating the Manchester Ship Canal;
(b) a tug not under way, but preparing to get under way or supplying power to other vessels or to shore installations;
20 minutes in the aggregate in any period of 1 hour.
(c) a vessel not under way but using main power for the purpose of dredging, lifting, pumping or performing some other special operation for which the vessel is designed.
5. Emissions from any other source
5 minutes in the aggregate in any period of 1 hour.

---
Source: https://www.legislation.gov.uk/uksi/1958/878/schedule (the official version)
Page: https://openlegislation.uk/dark-smoke-permitted-periods-vessels-regulations-1958/schedule
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.