|LBSCR Class E2|
|The first built E2 with short side tanks|
|V - E - T - D|
Additionally, the SR's chief mechanical engineer, Richard Maunsell, designed a tank engine similar to the E2's, which would eventually become the three-cylindered Z class 0-8-0. But due to the Z's high water consumption and the E2's being easy to maintain and drive, the three-cylindered tank engines did not replace them entirely.
Although the LB&SCR E2 tank engines traveled very short distances, their coal bunkers always were a massive problem. The bunkers were simply just too small to cope with many of the day to day situations of a shunting engine. The USA tank engines, for one, could work on branch lines easily. However, after two E2's were unsuccessfully tested on push-pull branch line services, they were sent elsewhere, due to the coal capacity being too low to cope. The most iconic feature, these engines have had, was the extended side tanks on the side. This was the famous design that had the top half of the side tank's front extended further. This is the prototype that Rev. W. Awdry's "Thomas The Tank Engine", is based upon.
Thomas has many differences to the E2. He is noticeably shorter in length, and has wheel arches, unlike his basis. He also has no dip at the back. This caused problems while pulling trains, as the buffers were uneven. To put an end to this, the Rev. W. Awdry created the story, "Thomas Comes to Breakfast". After Percy's incident, Thomas returned with his front dip removed. In later stories, however, Thomas has his front dip back. In the television series, Thomas has always had this front dip, even set his accident. Thomas is also number 1, while the E2's were numbered 100-112. Also in the television series, it was revealed that Thomas was originally number 70, a reference to 2015 being the 70th anniversary of the Railway series.
Only 10 of these tank engines were ever produced, and none have been preserved, due to their incredibly low coal capacity.
Ironically, even though they have been built to replace the Stroudley A1's and E1's, as well as Robert Billinton's E3's, the A1's (most having been rebuilt to A1x's) have outlasted them. Ten of the so-called 'Terriers' have been preserved, plus one E1. But like the E2's, none of the E3's have been preserved.