Thursday, 14 June 2012

Down to the nitty-gritty - Part 2: Some maths on operations

A question often hinted at in the independence debate is how many ships, aircraft or soldiers the Scots Army and Navy would have.

As with all figures, they need to be understood in context. The UK has 4 nuclear missile submarines, but no maritime patrol aircraft. Norway has no nuclear missile submarines, but 6 maritime patrol aircraft.
Taking the manifesto as a starting point, lets start with a look at the chart, and consider fishery protection as a driver for patrol numbers.

A view of the Scottish Economic Exclusion Zone (EEZ) 

Source: GERS 2007 [page 42]

Scotland's Exclsuive Economic Zone extends approximately 325 nautical miles west of Stornoway, and 300 nm north of Lerwick. The following chart superimposes two different sizes of radius of action, 100nm (10 hours steaming at 10 knots, as recommended by the 1995 Belton report into emergency tug stations) and 300nm, intercept range of a Typhoon fighter aircraft.

Typical operational ranges of ships and aircraft

Until last year two emergency Coastguard tugs were stationed in Scotland, at Lerwick and Stornoway, with the availability of commercial tugs from the oil port of Aberdeen considered to provide cover further south.

Today Marine Scotland runs three ships and two aircraft, and uses the VMS system to track foreign fishing vessels over 15m in length by satellite. According to an interview with a Marine Scotland captain, the 3 ships are double-crewed for a 3 weeks in 6 roster, and aim to board one fishing vessel per day using their crew of 15-20 sailors. 

According to a November 2011 article from the Royal Navy, who provide fishery protection south of the border, the 32-man complement (provided by rostering 43 people) of their three patrol boats board 2 fishing vessels per day and the patrol boats spend 85% of the year at sea. However this seen as exceptionally high availability and provides no margin for unexpected downtime. The rule of thumb typically used is 3 vessels to mount 1 standing patrol, to allow time for transit to and from patrol areas, crew training, and planned maintenance. The long-range (?) Trident patrol, with one boat always on station is provided from a pool of 4 boats.  To patrol Greenland, Denmark has 4 dedicated ships.

Assuming there is a desire to have a patrol vessel within a day's sailing of the bulk of Scotland's coastal waters then the three patrol areas outlined in the chart above, and the 3:1 force generation rule would suggest that at least 9 patrol vessels are required by the Scots Navy. Note that in 2007 it was planned that Marine Scotland was to have had 5 patrol vessels.

By way of comparison, the Norwegian coastguard (part of the Navy) operates 13 vessels, backed by 6 maritime patrol aircraft to cover 800,000 sq km of EEZ - Scotland's is 400,000. Also by comparison, the Irish Naval service operates 8 patrol vessels and 2 maritime patrol aircraft. Of interest is that neither the Royal Navy nor Royal Air Force have any such patrol aircraft.

For aerial surveillance Marine Scotland currently operates 2 aircraft with a maximum 1,200 nm range and cruise speed of 200 knots. Ireland's CN295 aircraft have a fully-laden range of 700 nm (maximum range approx. 2,300 nm) and cruise speed of 240 knots.

To have one MPA on a 1,200 nm / 6 hour circuit of the coastline at all times would require 3 aircraft. Again allowing for a force generation number of 2:1 would imply 6 aircraft. In an emergency situation 6 aircraft, fully available, could sustain a standing 24/7 patrol 200 nm from a host airfield.

This covers basic fishery protection - the question then becomes how many other tasks: emergency towing, oil rig firefighting, monitoring and boarding of non-compliant vessels other than fishing vessels, can a patrol vessel double up on? - that will be the topic of another post, likewise for the multiple roles of aircraft.

Of further interest, and again the subject of a future post, is the possibility of designing the next generation of inter-island ferries as dual role vessels, able to supplement the core force for more intensive patrolling in times of tension. Calmac is state-owned after all, and back in 1964 the government paid for three new ferries Columbia, Claymore and Hebrides, equipped to withstand nuclear contamination and designed to carry military equipment with vehicle deck heights to suit.

Independence "So Whats?"
1. Nine patrol vessels could sustain coverage of Scotlands key territorial waters

2. Six maritime patrol aircraft could sustain constant air surveillance of Scottish coastline
3. Royal Navy has no 
maritime patrol aircraft today

1 comment:

  1. doing initial surveillance by UAV would cut costs. this could cut actual surveillance aircraft.

    our patrol vessels need to be designed not just for fishing but for standby towing where they can hold rather than pull a large ship until heavy tugs arrive.