The release of the Telford train is set to be one of the main highlights from the Mamod factory this year.

It has been a long time coming for a model that was originally pitched way back in 2011. This four-year labour of love has been an absorbing time for everyone on both the design and production side. Mamod has scheduled the Telford to be released at the end of February and the excitement is already building for this latest locomotive.

The Telford train could also represent a new dawn for Mamod in terms of engine production. This model has embraced a new type of piston head which could become a regular feature on future train and steam models from the Smethwick factory. In our second look at the Telford we focus on the technical side of what has become known as the "runaway train" among its engineers.

Mamod has based the design of the Telford on the previously successful Saddle Tank models. It seemed only fitting as the company said goodbye to an old favourite towards the end of 2014. The final Diamond Jubilee Saddle Tank was sold in the build-up to Christmas, bringing an end to the long-running model.

The company has not rested on its laurels and as the final Diamond Jubilee Saddle Tank rolled off the production line, the release of the Telford edged closer. One of the key features of the Telford is Mamod's decision to install a vertical oil lubricator. This has allowed for a greater oil capacity, providing longer durations on a single full tank.

Another new feature is a top up port on the boiler which allows users to refill the engine without having to shut the train down. This innovative point will come in handy for users that are running the Telford as a much wider display. It will also be ideal for demonstrators when showing off their collections at major steam model events.

The piston heads have been the main focus of the Telford's innovation. Engineers have altered the shape of them to suit the needs of this new model. Previous Mamod models had seen the piston heads move back and forth, thus creating a lot of dead steam in the cylinders. The dead steam would not be utilised and this needed to be changed. Mamod's latest design ensures that all the steam is used and helps to increase power.

Mamod have now identified this method as the basis for all future engines. The company wants to install this new piston heads idea on to all of its slide valve range models which will make them much more efficient.

The runaway train – given the name after it was far too powerful during its first test run – is much heavier than many other models and has been increased two fold from the original design. This weight is handled by increasing the thickness of the chassis, it has also decreased the model's centre of gravity and making it more stable.

Having more weight on the axles has also meant that the wheels turn much slower and makes it a more controlled engine.

The Telford will make its debut at the end of February, heading into early March and will be available to purchase for Mamod directly.