Henry is a tender engine who lives on the Island of Sodor. He is engine No. 3 on the Fat Controller's Railway, and works on the Main Line.
Henry was originally built by either the Midland Railway or the LNWR around 1920 from plans stolen from Sir Nigel Gresley and was something like a cross between a GNR/LNER Class A1 and a GNR C1 Atlantic. He was sold to Sir Topham Hatt, who was desperate for a locomotive. The locomotive was a poor steamer, but since the only engines on the line were Edward, the Coffee pots, Thomas and some old W&SR locos, the Fat Director had no choice but to keep him in service. During this time two engines borrowed from the newly formed LNER arrived on Sodor, along with another which was to stay for the rest of his days.
Henry was vain and in August 1922 he stopped in a tunnel and refused to come out, citing that his paintwork would be spoilt by the rain. After several attempts to move him failed he was bricked up in the tunnel until Gordon broke down while pulling the Express. As Edward was unable to move the train himself, the Fat Director offered to let Henry out of the tunnel to help. Henry eagerly accepted. Henry performed very well, and the Fat Director promised him a new coat of paint, as his existing paintwork had been damaged more by his stay in the tunnel than it would have been by the rain. Henry asked to be painted blue like Edward. However, many people confused him with Gordon, to the bigger engine's annoyance. The matter was worsened after a trip to the Works where Henry was given spares of Gordon's buffers and cab. This caused Gordon to be very rude to Henry.
The poor engine and his system, which was already finicky at best due to design flaws, never really recovered from the stay in the tunnel. Henry developed steaming problems, about which he complained constantly, though he found little sympathy, especially when it caused him to be late.
Sometime before 1935 Henry, when again offered new paint, chose green to end the confusion. Unfortunately, he was to suffer humiliation when he was hosed with water by an elephant he frightened. After Gordon and James suffered humiliations of their own (and all three had become thoroughly fed up having to do their own shunting and fetch their own coaches), the big engines went on strike. The Fat Controller naturally disapproved of this nonsense, and after purchasing Percy he locked them in the shed for several days.
Later that year, during a period when the main line engines were being supplied with a poor delivery of coal, Henry was having a very difficult time of it indeed. He had strength to pull trains only sporadically, in spite of numerous parts replacements. At last the Fat Controller looked into it personally, and asked the opinion of Henry's fireman, who told him about the coal and suggested purchasing the high-grade Welsh coal the Great Western Railway used.
When the Welsh coal came, Henry's performance was vastly improved, such that he was comparable to Gordon. He continued to use the coal until February 1935, when due to a conjunction of a forced signal and frozen points he had a collision with a goods train at Killdane while pulling "The Flying Kipper" and was sent to Crewe to be rebuilt. Henry was rebuilt into a Stanier 5MT. (Sir Topham Hatt had connections with Sir William Stanier, so this may be the reason he managed to get Henry rebuilt so quickly).
After returning, Henry was added to the rotation for the Express, and pulled it so well that he made Gordon jealous. Gordon tried to get even by rudely critcising Henry for whistling loudly at stations, but had to eat his words later that day after his own whistle valve jammed open. Some time later, Henry was taking a slow train. As he passed under a bridge, four boys he had assumed to be railfans dropped stones on him and his coaches. He paid them out on his return journey by "sneezing" ashes that collected in his smokebox at them.
In 1952, when Queen Elizabeth II was to come to Sodor, Henry (rightly) assumed he was the Fat Controller's choice to pull the royal train. But the day before, while he was idling at the station his smoke blinded a painter, who fell along with his paint pot onto Henry. The paint splashed over Henry's boiler, and as painting over it would take too long for him to have time for the train Gordon was given the job instead.
When Duck arrived in 1955 to take over Percy's duties as station pilot, Henry, along with Gordon and James, teased him and tried to give him orders, as they had been doing to Percy. Duck, with Percy's help, blocked the big engines from entering the shed. The Fat Controller arrived and told the two tank engines off for causing a disturbance. Henry and the others laughed- until the Fat Controller shouted for silence, and told them they'd been worse, as they had made the disturbance. He told them that Duck was right about he, Sir Topham Hatt, being in charge. Henry respected Duck more after that.
Henry's good opinion of Duck would be briefly spoilt in 1957. He and the other main line engines were growing very tired of Duck's incessant talk about the Great Western Railway following City of Truro's visit. A Diesel sent to the island on trial quickly developed a grudge against Duck, and spread nasty stories about the main line engines to the trucks, stories he falsely claimed Duck had told him. Henry, furious at being called "Old Square Wheels", joined Gordon and James in barring Duck from the shed. He felt sorry a few days later when he became the next target of Diesel's slander, and when Duck returned after preventing an accident Henry cheered him loudly.
In 1963, he was later given a tender designed by Henry Fowler to replace his Stanier-designed tender.
When Gordon started feeling depressed in 1967, Henry, thinking Gordon was just moaning and groaning, teased him and told him he should get a wash-out, and would feel much better. When Gordon's younger brother Flying Scotsman visited Sodor, Henry was jealous of the visitor's second tender. Duck and Donald explained, and while Henry took the point he still was vain enough to want an additional tender. Duck, deciding to bring Henry down to earth, told the big engine that he had in his possession not one, but six spare tenders, which as a tank engine he had no need of. Henry accepted, and all the engines waited to see him go past. But instead of a splendid sight, the tenders were old, rusted, and full of boiler sludge! Gordon mocked him with a comment about wash-outs.
Henry was so frustrated that the day after 7101 and 199 arrived on trial he became so hot his regulator fused wide open, and his driver had to use the reverser to control him. On his return journey (no train), he stopped at a signal box next to 199, who had a train of oil tankers. The signalman told them that 199, who he nicknamed "Spamcan", had failed and that he needed to be moved out of the way to clear the line for the "Limited". Henry pulled the train clear. But shortly afterward, 7101's ejector failed and the "Limited" ground to a halt. Henry then volunteered to help move both trains. Luckily all he had to do for 7101 was keep the vacuum brakes off, but it was still hard work. The cavalcade made it to a station where Flying Scotsman waited to take the coaches, and Donald to take the goods. Henry brought 7101 to the Works afterwards, and days later cheered the arrival of Oliver.
In 1986, he was given splashers, mainly because of the fact larger driving wheels were installed to provide a faster mainline service when Gordon is busy.