232
A. NELSON-SMITH
in an underground pipe within 24 h and probably sooner in an underwater situation-although repairs in such a situation might take longer.
The points where pipelines pass under waterways and shipping channels
are the most liable to mechanical damage, from such natural causes
as bank erosion or a shifting bed as well as from dragging anchors
or dredging operations (Scherer, 1964). Such mechanical damage
represents the greatest danger of a pipeline. Many thousands of
gallons could be lost in a few minutes through a breakage (more than
175 000 gal-SO0 000 litres-were lost after sabotage of the Trans
Arabia line in November 19691, whereas it would take 28 days for a
30 gal/h leak to lose 20 000 gal (about 100 000 litres). This sudden loss
should be immediately detectable and could be minimized by stopping
the pumps and isolating the damaged section. The BE' pipeline has
twelve isolating valves ; its shortest section is one mile (1.6 km) long
and contains about 57 000 gal (250 000 litres). When a pipeline crosses
a waterway from which domestic supplies are drawn, it has been arranged that the water authority has control of these valves (see
Cunningham, 1954). It is also possible to place the operation under
automatic control-although a serious spill in Milford Haven resulted
from the failure of automatic shut-off equipment in the Waterston
refinery pipeline. Pipelines are none the less much more free from
accident than tankers and limitations on their wider use are largely
economic.
The pollution hazards associated with bulk oil storage are considered in a paper by Samson (1967) and in subsequent discussion. I n
Europe, covered tanks are used, often enclosed by an earthwork (bund)
sufficient to contain temporarily the entire tank contents. I n Venezuela, non-volatile fuel-oil has been stored successfully in open earthbanked reservoirs, the largest containing nearly 400 million gal (1 750
litres). Their cost is only 15% of conventional tanks, so it is possible
that in a highly competitive industry their use may spread. The risk
of pollution by seepage from a badly sited reservoir is obvious ; a less
obvious danger is indicated by North American experience with smaller
open sumps in which many waterfowl died, mistaking the oil surface
for water (King, 1952).
The bulk distribution and storage of oil is usually controlled by
skilled and responsible specialists. A much higher pollution rate, even
though on a smaller scale, results from oil-transfer operations at
engineering factories, garages, oil-fired heating installations, etc. by
personnel who have little knowledge of the proper procedures (Hogg
et al., 1947 ; McKee, 1956). I n waterside areas, surface drains empty
directly to the river, harbour or sea-shore ; waste cutting, lubricating
A. NELSON-SMITH
in an underground pipe within 24 h and probably sooner in an underwater situation-although repairs in such a situation might take longer.
The points where pipelines pass under waterways and shipping channels
are the most liable to mechanical damage, from such natural causes
as bank erosion or a shifting bed as well as from dragging anchors
or dredging operations (Scherer, 1964). Such mechanical damage
represents the greatest danger of a pipeline. Many thousands of
gallons could be lost in a few minutes through a breakage (more than
175 000 gal-SO0 000 litres-were lost after sabotage of the Trans
Arabia line in November 19691, whereas it would take 28 days for a
30 gal/h leak to lose 20 000 gal (about 100 000 litres). This sudden loss
should be immediately detectable and could be minimized by stopping
the pumps and isolating the damaged section. The BE' pipeline has
twelve isolating valves ; its shortest section is one mile (1.6 km) long
and contains about 57 000 gal (250 000 litres). When a pipeline crosses
a waterway from which domestic supplies are drawn, it has been arranged that the water authority has control of these valves (see
Cunningham, 1954). It is also possible to place the operation under
automatic control-although a serious spill in Milford Haven resulted
from the failure of automatic shut-off equipment in the Waterston
refinery pipeline. Pipelines are none the less much more free from
accident than tankers and limitations on their wider use are largely
economic.
The pollution hazards associated with bulk oil storage are considered in a paper by Samson (1967) and in subsequent discussion. I n
Europe, covered tanks are used, often enclosed by an earthwork (bund)
sufficient to contain temporarily the entire tank contents. I n Venezuela, non-volatile fuel-oil has been stored successfully in open earthbanked reservoirs, the largest containing nearly 400 million gal (1 750
litres). Their cost is only 15% of conventional tanks, so it is possible
that in a highly competitive industry their use may spread. The risk
of pollution by seepage from a badly sited reservoir is obvious ; a less
obvious danger is indicated by North American experience with smaller
open sumps in which many waterfowl died, mistaking the oil surface
for water (King, 1952).
The bulk distribution and storage of oil is usually controlled by
skilled and responsible specialists. A much higher pollution rate, even
though on a smaller scale, results from oil-transfer operations at
engineering factories, garages, oil-fired heating installations, etc. by
personnel who have little knowledge of the proper procedures (Hogg
et al., 1947 ; McKee, 1956). I n waterside areas, surface drains empty
directly to the river, harbour or sea-shore ; waste cutting, lubricating