Thomas has the most variations of any character in the Thomas Wooden Railway, with more prototypes, changes, and variants than any other character in the range.

Hank's model does not have a front coupler like other Wooden Railway engines and his television series appearance. Interestingly, Connor and Caitlin's wooden models have front couplers, while their front couplers are concealed in the TV series.Initially released with Bertram and the Scrap Cars; later reissued individually in 2012 and 2016 for limited release. Kevin's original 2009 model had red wheels instead of yellow. The prototype for his 2009 model was also colored green. At 25 years, Wooden Railway was the longest-running and most popular Thomas & Friends merchandise line (with ERTL being the second longest-running at 20 years). Some items were bundled with US DVDs and VHS tapes. Some were only available in these bundles, such as the Honey Barrel Car.

Flying Scotsman's reintroduced model features the British Railways logo with "Mainland Railways" printed in place of the British Railways text. In late 2016, some engines received smaller faces that no longer cover the whole smokebox front and others' faces were changed. While Whiff's model has the correct amount of wheels, this results in him being longer than engines who should be the same size as him. Features Soap-Sud covered Thomas with red funnel, soap suds covered Percy, bubble liquid car and hay covered Sir Topham Hatt's car.Fergus' reintroduced model has entirely white wheels despite his original model having the correct red wheels with a white rim. Volume VII (Note: Tiger Moth's propeller differs from the production model, suggesting the one seen here was a prototype)

In late 2017, twenty-five years after the debut of the Wooden Railway line, it was retired and replaced with Wood. The replacement was originally announced to take place in 2018, but ended up happening sooner. Early 2002 (new larger face, bigger smokebox, wide boiler, no ledge on rear, new details, shorter dome, funnel hole removed) In late 2011, TOMY bought out Learning Curve and as such acquired the rights to the Wooden Railway line. They sold the products previously planned to be released by Learning Curve for early 2012. The products due to be released in late 2012 coinciding with the special Blue Mountain Mystery were cancelled because Learning Curve had only developed the computer generated prototypes, before they were acquired by TOMY. Most of these cancelled releases with the new CGI style models were re-constructed by TOMY and sold under their name and a few others were later released by Fisher-Price. TOMY held the licensing until the end of 2012.The most famous of all the vehicles on the Island of Sodor, Thomas the Tank Engine is considered by all to be a "really useful engine". He is a cheeky, fussy little engine who is always eager to help. 2018 box description In the late 1990s and early 2000s, the line was overhauled and the majority of the models underwent major redesigns. The wooden funnel and smokebox were replaced with a separate plastic smokebox with a more realistic funnel. The tender engines received an additional upgrade, with a moulded plastic coal pile for their tenders. The second known prototype of Thomas seen features six red HEROS wheels, no coal bunker details, and a face borrowed from Thomas's ERTL die-cast vehicle. Thomas's very first prototype features four red wheels held in by nails, red and blue magnet guards, a wider chassis, no detailing, and no face. Features Winter Wonderland Thomas, Paint-Splattered Thomas and Breakfast Thomas; reissued in 2013 with the Breakfast Thomas being replaced with a Fish-Splattered Thomas.

Harvey's model's cab is oddly short to accommodate his hook. He is also brown instead of maroon red and does not have a boiler.The Talking Railway Series was a range of interactive engines and playsets. The engines have special gold magnets which, when they are at a destination, will prompt the Fat Controller to greet them. This range is discontinued.