All the funding for the new carriages comes from within the F&WHR family - the first has been financed by the FR Society; the second by the FR Trust; and the third by the WHR Society.
The new vehicles maintain the F&WHR's leadership position in the heritage sector in terms of passenger comfort and build on experience gained with the rolling stock purpose-built for the new Welsh Highland Railway, but to the smaller FR loading gauge, allowing them to be used on both railways on through services - the two main WHR carriage sets being too large to negotiate the restrictions of Garnedd Tunnel above Tan y Bwlch.
Work on the £100,000 carriage started at the company's Boston Lodge Works in late 2011. The entire vehicle, including underframe, bogies and body was fabricated in-house, incorporating key components from the previous 121, recently retired after thirty years' hard work. The new design was finalised following extensive testing of the prototype Super Barn, Carriage 103, which entered service in 2010.
F&WHR General Manager Paul Lewin said: "Passenger comfort is at the top of the priority list for all our carriages and 121 is no exception. Whilst remaining true to the design of the original 1960s 'barn carriages', 121 is one of the most advanced carriages ever to come out of our works.
"The result is an immensely comfortable carriage of which both Boston Lodge and the railway can be justifiably proud. We feel that the Super Barn design has produced a vehicle with a very high quality environment, offering good views and enhanced levels of comfort."
Each carriage is fitted with a diesel-fired Eberspächer heater mounted underneath. These devices were originally developed for luxury road coaches and have the benefit of being able to lift the temperature of a carriage to a comfortable level in couple of minutes. This is important if someone has left the doors open and the next group of passengers has been standing around in the cold prior to joining the train.
Adds Lewin: "We know that our passengers often travel as a group with friends or family. A trip on the railway is a social occasion, and if that is to work well then gathering around a table and facing each other is important. Airline style seating isn't conducive to social interaction and we therefore made it a policy to give everyone a table. Children can spend time with their colouring books whilst adults enjoy their coffee."
In the 1960s the Ffestiniog Railway began construction of a series of wooden-bodied carriages at Boston Lodge, using components manufactured by Watsons of Birkenhead. The design had been prepared by Boston Lodge volunteer Fred Boughey, who at the time was a lecturer at a technical college in Birkenhead and was thus able to oversee the manufacture of the components.
The design for the 1960s centenary stock was for a significantly larger carriage than all previous designs, the restriction on height imposed by the original Rhiw Plas road bridge having been removed by road improvements. The profile was based on that of the restored former Lynton and Barnstaple Carriage 14 and this, combined with the spacious interiors caused these carriages to be given the affectionate nickname, 'The Barns'.
Several of the original Barns have travelled well over half a million miles in service - the equivalent of a return trip to the Moon.