Date | Section of line | Broad | Mixed |
| 1 Jan 1867 | Total mileage | 905m 43c | 330m 48c |
| 18 Apr 1867 | Portishead branch1 | 9m 49c | |
| 17 Jun 1867 | Exeter City Basin branch3 | 0m 34c | |
| ? Nov 1867 | Highbridge-Durston-Yeovil (mixed)1 | 32m 49c - | 32m 49c |
| 28 Feb 1868 | Churston - Brixham7 | 2m 6c | |
| ? Apr 1868 | Bridgend - Tondu (mixed)4 | 3m 4c - | 3m 4c |
| 25 May 1868 | Princes Risborough - Aylesbury (to standard gauge) | 7m 27c - | |
| ? Aug 1868 | Lattimer Rd Junction - Hammersmith (to standard gauge)2 | 1m 37c - | |
| 12 Nov 1868 | Yeovil Town - Pen Mill (mixed)1 | 0m 40c - | 0m 40c |
| 1 Apr 1869 | Oxford - Wolverhampton + branches (to standard gauge) | 90m 9c - | |
| 1 Apr 1869 | Reading - Basingstoke (to standard gauge) | 13m 49c - | |
| 19 Apr 1869 | Lydney Junction - Wimberry | 8m 19c | |
| 1 Jun 1869 | Lostwithiel - Carne Point5 | 4m 60c | |
| 1 Jul 1869 | Burngullow - Drinnick Mill6 | 3m 10c | |
| 3 Aug 1869 | Yatton - Cheddar1 | 9m 65c | |
| 14 Aug 1869 | Grange Court - Hereford (to standard gauge) | 21m 36c - | 1m 15c - |
| 20 Aug 1869 | Gloucester - Grange Court + docks branch (mixed) | 9m 2c - | 9m 2c |
| ? Nov 1869 | Dunball Wharf branch1 | 0m 36c | |
| 5 Apr 1870 | Cheddar - Wells1 | 7m 57c | |
| 23 Aug 1870 | Maidenhead - Oxford via Wycombe (to standard gauge) | 36m 58c - | |
| ? Mar 1871 | Bridgwater docks extension1 | 0m 28c | |
| 20 Mar 1871 | Exeter City Basin branch (mixed)3 | 0m 34c - | 0m 34c |
| 8 Jun 1871 | Norton Fitzwarren - Wiveliscombe1 | 7m 25c | |
| 6 Oct 1871 | West Drayton - Uxbridge (to standard gauge) | 2m 51c - | |
| 31 Dec 1871 | Total mileage | 844m 65c | 270m 58c |
| Metric conversion: 80 chains = 1 mile; 5 miles = 8 kilometres | |||
| Note 1: | Bristol & Exeter Railway | ||
| Note 2: | Hammersmith & City Railway | ||
| Note 3: | South Devon Railway | ||
| Note 4: | Llynvi & Ogmore Railway | ||
| Note 5: | Cornwall Railway | ||
| Note 6: | Cornwall Minerals Railway | ||
| Note 7: | Torbay & Brixham Railway | ||
Locomotive Class | No. (+/-) | Total | |
| 1 Jan 1867 | Total locomotives | 509 | |
| Star 2-2-2 | - 9 | 0 | |
| Fire Fly 2-2-2 | -27 | 16 | |
| Sun 2-2-2 | -11 | 6 | |
| Leo 2-4-0 | -11 | 3 | |
| Hercules 0-6-0 | - 4 | 0 | |
| Great Western 4-2-2 | - 1 | 0 | |
| Prince 2-2-2 | - 6 | 0 | |
| Iron Duke 4-2-2 | - 3 | 26 | |
| Premier 0-6-0 | -10 | 1 | |
| Pyracmon 0-6-0 | - 1 | 5 | |
| Bacchus 0-6-0 | - 1 | 0 | |
| Bogie 4-4-0T | - 2 | 13 | |
| Waverley 4-4-0 | 10 | ||
| Victoria 2-4-0 | 18 | ||
| Ceasar 0-6-0 | - 1 | 7 | |
| Banking 0-6-0T | - 1 | 3 | |
| Standard Goods 0-6-0 | - 3 | 99 | |
| Metropolitan 2-4-0T | - 1 | 21 | |
| Hawthorn 2-4-0 | 26 | ||
| Swindon 0-6-0 | 14 | ||
| Sir Watkin 0-6-0T | 6 | ||
| Iron Duke Renewals (Rover) 4-2-2 | + 3 | 3 | |
| B&ER 4-2-2 | - 6 | 13 | |
| B&ER 0-6-0 | 18 | ||
| B&ER 4-2-4T | 6 | ||
| B&ER 4-4-0T | +10 | 20 | |
| B&ER 2-2-2T | 7 | ||
| B&ER 0-6-0T | + 2 | 3 | |
| B&ER 2-4-0 | + 8 | 8 | |
| VofNR 4-4-0T | 9 | ||
| VofNR 0-6-0T | 10 | ||
| SDR 4-4-0T | 35 | ||
| SDR 0-6-0T | + 1 | 17 | |
| SDR 0-4-0T | + 1 | 1 | |
| SDR 2-4-0T | + 2 | 2 | |
| CCR 4-4-0T | 4 | ||
| TBR 0-4-0T | + 1 | 1 | |
| Unclassified engines | - 7 | 1 | |
| 31 Dec 1871 | Total locomotives | -77 | 432 |
| Key: | B&ER - Bristol & Exeter Railway VofNR - Vale of Neath Railway (merged with GWR Dec 1866) SDR - South Devon Railway CCR - Carmathen & Cardigan Railway TBR - Torbay & Brixham Railway | ||