by Werner » Tue Feb 19, 2008 6:48 pm
Looking aside from propellers for a moment, many USN warships were designed and commissioned with "cruising turbines", which is a separate stage in the turbine system. When they were in use, low and medium speeds could be attained with great efficiency. Before 1910 or so, the USN decided a range of 10,000 miles and a cruising speed of 10 knots were necessary for their mission of traveling as a fleet from San Pedro (Los Angeles) to Manila and arriving able for combat.
With it's vast system of bases and alliances, the RN could afford smaller, shorter range ships. From a strategic standpoint, the British ships were not designed to steam halfway around the world for a major fleet engagement, but rather to protect certain trade routes against cruisers and armed merchant cruisers. As a result, their ships were designed to be most efficient at 19 knots, rather than the 10-15 knots of American ships.
None of this relates to the maximum speed, since no fleet commander would expect more than a few days at top speed; the amount of maximum power fit to a ship to achieve the maximum speed is a strategic decision taken at other levels, and it only effects the amount of machinery crammed into a particular hull. Very little of the design for cruising or optimal speed can be tailored to also benefit top speed.
In addition, there is the ability to accelerate. The USN Adams class destroyers were admired by many navies for their ability to accelerate from cruise to maximum speed without 'breaking a sweat', while more powerful ships nearly required an 'act of God' to get rapidly to top speed.
The Italian Navy of the 1930s and to a degree the French Mediterranean Fleets had different needs. They had very short distances to travel, and so could disregard the need for endurance and damage control, since they were usually only a few hours from a major yard.
Looking aside from propellers for a moment, many USN warships were designed and commissioned with "cruising turbines", which is a separate stage in the turbine system. When they were in use, low and medium speeds could be attained with great efficiency. Before 1910 or so, the USN decided a range of 10,000 miles and a cruising speed of 10 knots were necessary for their mission of traveling as a fleet from San Pedro (Los Angeles) to Manila and arriving able for combat.
With it's vast system of bases and alliances, the RN could afford smaller, shorter range ships. From a strategic standpoint, the British ships were not designed to steam halfway around the world for a major fleet engagement, but rather to protect certain trade routes against cruisers and armed merchant cruisers. As a result, their ships were designed to be most efficient at 19 knots, rather than the 10-15 knots of American ships.
None of this relates to the maximum speed, since no fleet commander would expect more than a few days at top speed; the amount of maximum power fit to a ship to achieve the maximum speed is a strategic decision taken at other levels, and it only effects the amount of machinery crammed into a particular hull. Very little of the design for cruising or optimal speed can be tailored to also benefit top speed.
In addition, there is the ability to accelerate. The USN [i]Adams[/i] class destroyers were admired by many navies for their ability to accelerate from cruise to maximum speed without 'breaking a sweat', while more powerful ships nearly required an 'act of God' to get rapidly to top speed.
The Italian Navy of the 1930s and to a degree the French Mediterranean Fleets had different needs. They had very short distances to travel, and so could disregard the need for endurance and damage control, since they were usually only a few hours from a major yard.