Why warship numbers matter

This is a quick piece inspired by a post on Twitter:

Around 50 years later we are in the absurd position that the RN has just 13 frigates in total, has not commissioned a new frigate since 2002 and will not receive another frigate before at least 2020. The Defence Review currently underway is pondering whether the RN can have the 13 Type 26 frigates needed just to maintain escort ship numbers at a grand total of 19.

It was quickly pointed out that the new Type 45 destroyer and the Type 26 frigate are bigger and vastly more powerful that the Leander and Tribal class Frigates of the 1960s. This is very true but the excuse that “each generation of warship is more powerful that its predecessor so we can reduce numbers” (frequently trotted out by politicians and even the odd Admiral) is totally flawed for several reasons:*

  • Most of our adversaries warships are also more powerful and they have upgraded their capability just as we have. It is therefore very unwise to assume we gain significant qualitative advantage with every new generation of vessel. Despite the quality of today’s surface ships, the sophisticated array of threats they face now are arguably more challenging than they have ever been.
  • The world’s oceans are still as vast as ever. One vessel can only be in one place at once. New sensors and networking capabilities may have increased in range and coverage but not that significantly.
  • Sod’s law still applies. Vessels still suffer breakdowns, reliability problems (even expensive new ones such as the Type 45) & occasional accidents. You need numbers to mitigate this by providing substitutes and a ‘plan B’.
  • Numbers offer tactical flexibility. A navy with that plenty of vessels forces the enemy to deal with threats from multiple directions. Fewer vessels can threaten on fewer axis making defence easier.
  • Keeping some forces in reserve is a fundamental part of any military strategy. A small navy, however capable its individual vessels, have insufficient ships to form a reserve. A reserve maybe needed to replace combat losses, respond to sudden changes in enemy disposition or offer the option to concentrate vessels together into an overwhelming force.
  • A small navy can’t accept losses. The RN has historically been willing to lose ships as a tactical necessity in order to win the strategic advantage. A study of RN history will reveal apparently disastrous loses of ships, submarines aircraft and men but accompanied by equally frequent magnificent long-term victories.
  • As ships cannot remain on station indefinitely, a small navy cannot sustain long-term operations with sufficient numbers on the frontline. Many naval operations last months or even years and require a sustained rotation of vessels. An approximate rule of thumb says 1 ship on station requires 3 vessels; one on the frontline, one in transit and one in refit or undergoing training. Supposedly less maintenance-intensive new platforms and creative approaches to crew rotation may mitigate this slightly but not enough.
  • Presence and visibility itself can be a deterrent. The dispatch of warships to trouble spots or just frequent visits can be a factor in maintaining peace and stability as well as acting as ambassadors to promote good relations and trade. A small navy becomes invisible, losing this great, but often under-valued benefit to the nation.


Unfortunately as the sophistication of naval warfare has advanced, the price of individual platforms has increased far ahead of inflation. An under-funded RN has therefore been forced to choose between quality and quantity and has decisively gone for quality. Despite frequent criticism, the RN is right to prioritise high end vessels as it is almost pointless having a large fleet of ships lacking the full range of real fighting capability.

Nevertheless there is no escaping the conclusion, what is really needed is the political will to fund a larger navy with additional first-class warships, ideally with an expanded ‘second tier’ of cheaper but more numerous constabulary vessels supported by unmanned systems.

There is some hope that ‘cheaper’ unmanned systems may offer a partial solution to lack of numbers. Unmanned aircraft are leading the way for now with underwater systems developing. The unmanned warship maybe a while off but will surely happen. It is encouraging to see the current RN leadership is embracing this area of innovation.

*Many of these principles are ancient and apply to all forms of warfare
(See also Sun Tzu’s ‘The Art of War’ c400BC)