The Festiniog Railway uses four standard types of couplings. Some items of rolling stock may have non-standard couplings. The four standard couplings as given in the rule book are: Hook and Link, Screw, Norwegian (Chopper), and RAF-Type.
Hook and Link
The earliest wagons (or waggons, if you prefer) on the FR would be the early wooden slate wagons. The survivors of these have the floors and framing protruding at the end in a horizontally-curved shape which is faced with iron to provide a buffing surface. Beneath this hangs a link to which is attached a hook for coupling. To couple, the hook is simply connected to the link on the next vehicle. The links are attached to the ends of an iron bar which runs the length of the wagon below the floor in order to carry the traction force through the wagon without straining the wooden frames.
The iron slate wagons had iron dumb buffers with a similar hook and link beneath. These wagons have a central spine to carry the traction and buffing loads which is formed of angle iron, or in some cases old lengths of double-head rail. Other wagons from the early years had a small spring buffer or a dumb buffer with hook-and-link below.
The England engines when they appeared from 1863 had a central spring buffer with hook and link, and this remained the standard for locomotives throughout the pre-revival period, but with a few exceptions.
Some vehicles (Brake vans, England Engine Tenders and the early Bogie Waggons) had a light chain from the back of the coupling hook to some point on the bodywork or the end handrail, to enable uncoupling from within the vehicle when shunting. These are not now fitted.
Hook and link couplings are fitted to most of the historic goods stock, but are not now used on the main line without additional retention. This sometimes takes the form of a plastic cable tie across the jaw of the hook.
When the earliest carriages, the Small Birminghams, appeared they were fitted with generously-sprung central buffers with a fixed hook beneath at the top end, and they were coupled by small screw couplings attached to the bottom end of each carriage - see iBase 187-192. This arrangement may still be seen on Carriage 3, Carriage 4 and Carriage 11 (the Flying Bench - though this has a fixed hook at the lower end and hook-and-link at the upper end), but other survivors have been altered to chopper couplings.
Locomotive James Spooner when new in c1872 ran for a while with a unique arrangement (at the bottom end only) of a fixed hook below the buffer to accommodate the screw couplings with the addition of a captive link to accept hook-and link couplings on wagons, but after a few years (certainly by 1887) was altered to the standard hook-and-link arrangement as on other locomotives. The top end of the engine is believed to have had standard hook-and-link from new and is so shown in Vignes (1878).
The Small Birminghams were customarily marshalled at the top end of passenger trains, between the locomotive and the bogie carriages. The hook-and-link on the loco was coupled to the hook of the screw-fitted carriage by using a single loose link - this may be seen in use in iBase 175, and hanging loose on the top end of a carriage in iBase 1913. The early arrangement on James Spooner was clearly intended to avoid the use of this loose link, but seems to have been unsatisfactory for an unknown reason.
The later Quarrymen's Carriages were formed into semi-permanent sets of three or four, with screw couplings within the sets and hook-and-link at the ends. The survivor, Carriage 8 has hook-and link at both ends with spring buffers.
Norwegian or Chopper type
Norwegian, more commonly called chopper couplers, consist of a central buffer, with a pivoted hook that drops into a slot in the central buffer. This general type of coupling exists in many different forms and variations which are not necessarily compatible, even assuming that they are both the same height above rail level.
These first appeared on the FR on the pioneering bogie coaches of 1872, Carriage 15 and Carriage 16. The engravings in Vignes' Etude Technique ,  of 1878 show two different versions of couplings on these carriages.
The early type shown as 'Premier Attelage' has a slot in the buffer head only wide enough for one coupling hook, so the other one has to be held up by a light chain from the upper 'horn' of the chopper attached to the handrail on the end platform of the carriage. The pin with which the coupling hook engages has an eccentric to take up the slack with a weight on an arm to keep the couplings closed up, but the pin on which the coupling hook pivots does not. The early photograph dated 1872 as normally reproduced in print is unclear due to deep shadows in the coupling area, but it now appears on the FR/WHR Online Archive  with improved detail in the shadows, and it may be seen that the coupling is as drawn in Vignes.
The buffer head is square, the slot dividing the buffer head runs the entire height of the head, dividing it into two separate pieces, the weight on the arm can be seen and the upper horn of the chopper is prominent. From this protrudes a horizontal pointed article which is in fact the fitting for attachment of the suspension chain which is not present, apart from a short length hanging from the eye on the handrail. This fitting is forked to embrace the upper horn, to which it is pivoted, and at its outer end there is an eye for attachment of the chain. (This fitting has been interpreted by previous writers as a horizontally-protruding spike which is part of the chopper itself, but it is now apparent that this is not so.) There is also a loop below the buffer, to accept the hook of a hook-and-link coupling. When this is in use the chopper can be held up out of the way by use of the chain.
The 'Dernier Attelage' is an improved type, and has the slot wide enough for both hooks to engage, and the hooks are pivoted on the same pins that the opposing hook engages with, which means that the eccentrics can take up twice as much slack. The second pin in each coupler head is only to prevent overtravel of the coupling hook. The suspension chain is no longer required. The loop to accept hook couplings is not shown by Vignes, and there is no means of holding the chopper out of the way, but as these are shorter and pivoted further out, they can be laid back out of the way when not required. It is not evident from Vignes' drawings if the buffer head is round or square, but in this type also the slot is full height and the head is divided in two parts. No clear photo of the 'Dernier' type has been seen.
It would appear that the first version (the 'Premier' type) was in accordance with a patent described by G. P. Spooner in 1874 (27 January). The 'Dernier' type may have been developed by William Williams at Boston Lodge, who later wrote 'I remember years ago the eccentric had a balance weight on... this was a failure, the inventor Mr Spooner allowed me for safety to put the present right and left coupling on'  though the 'Dernier' still has the weights on the eccentrics. The 'right and left' allusion could refer to the two hooks engaging. No date is given for Williams' improvement. One wonders why Vignes bothered to include the 'Premier' type if it was unsatisfactory and had been superseded, unless the changeover was gradual and some of the old type were still in use.
There is probably still scope for additional research in this area.
The couplings are mounted on long bars which are attached to pivots on the frame crossmember above the bogie pivot pin, protruding through slots in the buffer beams (or what would be the buffer beams if the buffers were attached to them) allowing them to radiate according to the curvature of the line.
The maker's photograph of the original Taliesin shows it fitted with chopper couplings similar to the NWNGR type, but it must have been altered at a very early date to standard hook-and-link and appears so in all photographs in service. The rear coupling in this condition is unusual in that the springs are internal (under the bunker) and the coupling links are attached to the bottom of the buffer head.
There is a photo  of Prince on the WHR in 1925 with a chopper at the front, but other FR engines worked on the WHR without modification. By 1927 Prince was back to normal. When Palmerston was hired to the Vale of Rheidol for several summers before the First War he was fitted with VoR pattern chopper couplings but reverted to standard when back at home.
All subsequent c19 bogie carriages had chopper couplings. Some pictures show a link hanging beneath to allow coupling to hook-and-link stock. Passenger brake vans had a chopper at the uphill end to couple to bogie carriages, and hook-and-link at the downhill end for empty slate wagons going uphill or coupling to the loco on Down trains.
In early revival days it was decided to fit all passenger locomotives with chopper couplings, though Palmerston still has hook-and-link as he was restored away from the Railway, as a historical showpiece, and only later returned to the Railway.
All modern carriages including those for the WHR/RhE have chopper couplings. Some couplings were acquired from the Welshpool & Llanfair Light Railway in the early revival period and it is understood that these were used on Moelwyn and Carriage 14 and other items, but these may have needed modification as the W&L type did not have the eccentric and weight arrangement. Nowadays couplings are made at Boston Lodge, and most of those in use today are circular and have the slot only in the upper half. Those of recent manufacture also have a semicircular notch in the bottom below the slot. All new couplings feature a 'french pin', or at least a hole for the same, for coupling to hook and link stock. The ones in use vary considerably in detail but it would take an expert to identify the origin of some examples.
The coupling is 1ft 5 1/2 inches above the rail. 
Norwegian use of the chopper coupling
The first low cost narrow gauge railway in Norway opened in 1862, a few years before steam power was introduced to the FR. . The first two lines used a kind of link and pin coupling.
The Norwegian chopper coupler was introduced in the third Norwegian narrow gauge line in about 1866. Steam arrived on the FR in 1863.
The engineer of the Roros Railway travelled often to England, was a member of the UK Institute of Engineers, and adopted a gauge that was a round figure in imperial measurement, all the better to persuade English engineers to the narrow gauge cause.
The conventional twin buffer and chain found on standard-gauge lines would have been unsuitable on really sharp curves, where some kind of centre buffer-coupling would have been more suitable.
So it is suggested that the Festiniog Railway was influenced by the Norwegian Narrow Gauge railway coupling, or perhaps vice versa.
Possibly better described as 'Hudson type' or 'Industrial type'. Most of the relatively modern wagons acquired in the revival period are of Hudson make and have a central dumb buffer with link and pin couplings on top. These include the so-called RAFs, MoDs, Locoals and the large Skips. This type of coupling is typical of industrial railway practice, and most small industrial-type locos (and Harlech Castle until fitted with choppers in 2015) can couple directly to these, but adaptors are required for coupling to chopper or hook-and-link stock.
When the connecting line to the new Welsh Highland Railway opened in 1923, both railways (WHR and FR) were under common management and it was decreed that passenger stock should be pooled. The ex-NWNGR stock had chopper couplings on locos and carriages which looked similar to the Spooner type but turned out to be not entirely compatible. This came to a head on 1 July 1924 when a train of mixed stock came uncoupled in Moelwyn Tunnel and both portions were stopped in the tunnel by the parting of the brake pipes. The carriages which separated were actually both ex-NWNG vehicles but had been coupled by an FR man, possibly incorrectly, and the side chains were not coupled at all. Following this embarrassing incident (despite the suggestion of operational error) the NWNG couplers were altered by extending the slot from the top of the buffer to the entire vertical diameter, thus separating the two halves of the buffer head. This made them more like the FR type of the 1870s, and meant that the hook of hook-and-link stock could be hooked on to the pin in the coupler shaft. Also the choppers were replaced, the new ones on Russell looking particularly agricultural.
After the departure of H. J. Jack in November 1924 coaching stock was generally kept in rakes of similar origin and there was less mixing of stock (though it did occasionally happen).
NWNG coaches and locos also had side-chains, which the FR did not (Moel Tryfan did not have these at the front, but did at the rear).
NWNG wagons had hook-and-link, though some had two links, which meant that the hooks could drag on the ground which must have been a nuisance. Some wagons also had side-chains but not all.
War Dept couplings
In the early 1920s several items of WD type rolling stock appeared on the Railways, namely the Simplex and Baldwin tractors, Baldwin 590, the Hudson Toastracks and the WD Bogie Waggons. These had a rectangular central buffer with a slot in the top which were coupled not with choppers but with two-hole links between horizontal pins in the coupler shafts. These must have been difficult to couple to other stock and after about 1924 photographs show that the buffer heads were inverted so the slot was at the bottom. The cross-pin could then be used for a link and hook. This change may have been a follow-on from the mod programme for the NWNG couplings. The Hudson works photo of Toastrack 41 shows the buffer with the slot at the top.
EAG Wagons ex-RNAD
Originally had RNAD type bell-mouth couplers, but these have been altered to choppers (5002,3 have choppers one end and link-and-pin the other so they can be used as adaptors).
SAR Link and pin
The wagons from South Africa came with SAR type link and pin couplers, where the link goes in the middle of the buffer part rather than the top. As these wagons have been overhauled for service they have been fitted with choppers, with goose-necks to get the height correct. Exceptions are the pair of Flat Wagons Converted To Rail Carrying Bolster Wagons, which retain the SAR couplers at the inner ends only, separated by a long bar, for carrying rails, which are 60 feet long.
Couplings are normally mounted on the mainframe of rigid locomotives and on the bogies of articulated locomotives. On bogie rolling stock they are mounted on pivots inboard of the vehicle ends, near the bogie pivots, except for a few types on WD type or Polish plate-framed bogies, which are mounted near the vehicle ends, and are designed to carry the couplings. See Hudson Toastracks, waggon 57, and gallery below.
Norwegian narrow gauge
chopper coupling of about 1866.
The hook is at one end only.
loco Moelwyn - chopper
B wagon - original SAR coupling
B wagon - converted FR coupling
note "gooseneck" to lower height of coupler
loco - chopper (Norwegian) (zoom)
B wagon - original SAR coupling (zoom)
B Wagon - converted to FR with Gooseneck (zoom)
wagon 98 - link and pin
wagon DZ2001 - SAR coupler and long spacing bar
(incomplete and cluttered view)
wagon 98 - link and pin (zoom)
EAG - coupling original
SAR coupler and long spacing bar (zoom)
Prince - coupler in dark (hard to see)
Carriage 26 showing
brake and electrical connectors
Waggon 140 - chain and hook
Slightly different shape of FR coupling.
Link and Pin coupler on Gertrude.
Brake hose (left) next to
electric connector (right) (detail)
Link & Pin coupler on locomotive Gertrude (zoom)
Buffer and Hook of locomotive Princess.
Buffer and Hook on The Flying Bench No. 7
Coupling of Waggon 57 mounted on bogie
Coupler Buffer & Hook on Princess.
Coupler Buffer & Hook No. 7 The Flying Bench.
FR Coupler mounted on bogies of Waggon 57.
Chopper coupling, side chains and fittings from unidentified ex-NWNGR carriage; shows otherwise hidden drawgear.
Buffer over Hook on James Spooner loco 1874.
Hook and link couplings can be coupled to chopper fitted vehicles using a "French Pin" that is inserted through the chopper to give bar for the hook.
RAF wagons can be fitted with adaptor blocks to couple RAF to chopper or hook and link vehicles. Similar adapters are available for coupling MOD to chopper or hook and link. RAF to chopper adapters have become much more common place since the fitting of chopper couplings to Harlech Castle. Other adapters include one used to convert Van 2's rear buffer to a chopper.
In early 2015, Harlech Castle was in Boston Lodge, and the couplings were changed to choppers as part of a coupling standardisation programme.
A rake of wagons may have FR chopper couplings at ends and a different coupling in between.
Brakes and electrical couplings
Various services besides the all important couplings need to be "coupled" together, including:
- Locoals - wagons fitted with link and pin couplings.
- Flat Wagons Converted To Rail Carrying Bolster Wagons - rake of wagons with FR coupling at ends and SAR coupling in between.
- Moelwyn - good picture of FR coupling.
- EAG Wagons
- FR Bolster Wagons - some close coupled sets.
- B Wagons - with original SAR coupling, and later with FR coupling.
- Carriage 123 - electrical coupling
- Mobile workshop set - permanently coupled set.
- WHRL Coach No. 8 - automatic central couplings and safety chains.
- K-class Garratt locomotives had couplers on bogies rather than frame.
- Vignes, Edouard (1878). Étude technique sur le Chemin de fer de Festiniog et quelques autres chemins de fer à voie étroite de l'Angleterre. Paris: Dunod. OCLC 26025340. (also reproduced in part in Boyd)
- Vignes, Edouard (1986) . Technical study of the Festiniog Railway and some other narrow-gauge railways of England. Translation:D. Boreham. London: P.E. Waters & Assoc. ISBN 0948904038. OCLC 17354030.
- Boyd, James I.C. (1975) . The Festiniog Railway 1800 - 1974; Vol. 2 Locomotive and Rolling Stock and Quarry Feeders. Blandford: The Oakwood Press. ISBN 085361-168-8. 1975 edition p357, source not given
- Boyd, James I.C. (1989). Narrow Gauge Railways in South Caernarvonshire, Vol. 2, The Welsh Highland Railway. Blandford: The Oakwood Press. ISBN 0-85361-383-4. p38+2
- iBase 1473
- iBase 1434
- original drawing of Taliesin (iBase 29)
- Welsh Highland Heritage No 30 p3
- Boyd, James I.C. (1975) . The Festiniog Railway 1800 - 1974; Vol. 2 Locomotive and Rolling Stock and Quarry Feeders. Blandford: The Oakwood Press. ISBN 085361-168-8. plate 10R