The Hattons ‘OO’ gauge Class 66 has an impressive specification, and DC Kits’ Legomanbiffo has created an equally high value sound decoder specifically for the model. MIKE WILD installs an ESU LokSound V5 decoder into the Hattons model together with stay alive and a ‘rail rumble’ speaker.

THE CLASS 66 is the prime freight locomotive on the British railway network today with more than 450 in service with five different operators hauling everything from biomass fuel to oil, iron ore, container trains, rubbish, nuclear traffic, engineering trains and more. 

Since the pioneer entered traffic in 1998 with EWS, they have been a hot topic for ready-to-run models. The first for ‘OO’ gauge came from Lima, and that model lives on through Hornby, which was later joined in the early 2000s by a high definition version with modern chassis from Bachmann. Fast forward 15 years and Hattons chose this modern day workhorse for a home-grown all-new ready-to-run locomotive in ‘OO’ gauge which it delivered in the early months of 2020.

In total, 37 versions have been produced covering a broad cross section of liveries and sub-classes consisting original EWS maroon and gold, DB branded maroon and gold, DB Schenker red and grey, Freightliner, DRS, Colas Railfreight, GBRf and unique liveries such as Cemex, Biffa red and orange and BR ‘large logo’ blue as 66789. All have era and sub-class specific details making the Hattons Class 66 the most detailed ‘OO’ gauge model of the Co-Co heavy freight locomotive yet. You can read our full review in HM152 (February 2020) or at KeyModelWorld.com in the Reviews section.

Above: The completed model offers a superbly realistic driving experience with authentic sounds reproduced through the powerful ‘rail rumble’ speaker. We adjusted CV5 (maximum speed) to 80 and CV6 (mid-speed) to 35 to suit our driving style.

Here we are focused on the digital sound options for the Hattons Class 66. There is a factory fitted sound option from Hattons, but here we are using Legomanbiffo’s comprehensive sound decoder for the ‘66’ on an ESU LokSound decoder. This makes full use of the lighting function on the model through function keys with manual control over directional lights (with light engine and train modes), parking lights and even night mode too. In addition there are also options to adjust the horn tone and spirax valves to suit different periods of the ‘66s’ career.

Installing a sound decoder is straightforward with the only difficult part being removal of the body because of the lower cab steps – this requires the body to be carefully spread to lift the steps over the die-cast chassis for safe removal of the body. Once the body is off, there is clear access to the lighting switches as well as the 21-pin DCC decoder socket. There is also ample space to install a 65mm x 29mm Earth Mover 2 speaker in the speaker well, as designed in by Hattons. Our installation also covers the addition of an ESU stay alive pack and while this is designed to provide three seconds of on board energy storage, in reality we found it offered around five or six seconds with the locomotive sounds running – a great addition for reliability in service.

The following step by step guide shows how we installed the ESU LokSound V5 decoder with Legomanbiffo sounds into the Hattons Class 66 to give 66088 a new lease of life. 

Product Supplier Cat No.
Class 66 66088, DB branded EWS maroon and gold www.hattons.co.uk H4-66-005
Legomanbiffo Hattons Class 66 sound file, LokSoundV5 www.dckits-devideos.co.uk LB-Class 66 (Hattons)
'Rail Rumble' Earth Mover 2 speaker www.dckits-devideos.co.uk Spk-Earth Mover
ESU stay alive pack www.dckits-devideos.co.uk 54671

The Class 66 is seen across the length and breadth of the country on freight traffic. DBS Class 66 66031 climbs away from Ipswich with 6Z57, the 12.02 Ipswich Griffin Wharf -Watford, on September 8 2014. John Day/Railphotoprints.uk.


Hattons' 'OO' gauge class 66 features an advanced specification of lighting which Legomanbiffo's ESU sound decoder accommodates fully. With the addition of an Earth Mover 2 (also known as 'Rail Rumble') speaker installed, the model really comes to life.

The body of the Hattons Class 66 is a clip fit over the metal chassis, but it has one complication – the superdetailed lower cab handrails and steps. Caution needs to be exercised when lifting these over the chassis. Take it one corner at a time.

Once the lower handrails are against the chassis block, it is plain sailing to lift the body clear of the chassis. Check each corner by raising the body a little at a time.

With the body off, the complexity of the chassis is on show. Six lighting switches are provided which allow all users to take advantage of the features of the circuits through either analogue or digital control. There is also a large space for a speaker and a 21-pin decoder socket. 

As delivered, all switches on our sample were set to the ‘up’ position. These need to be adjusted to suit the ESU LokSound decoder.

As outlined in the instruction sheet, switches K3 and K6 were moved to the ‘down’ position to set the lighting up for use with the LokSound decoder.

The decoder for this installation is ESU’s latest generation LokSound V5 21-pin chip. It comes pre-connected to a 15mm x 11m cube speaker and also has a three-wire (red, white and black) connection for a stay alive capacitor.

The speaker for our project is an Earth Mover 2. The Hattons chassis has been designed to accept this speaker facing down, but a little adjustment of the factory wiring is required to allow it to fit.

To make manipulation of the wiring easier, we detached the lighting connection bar and plastic mount. This allows the speaker to be slid underneath the remaining wires to set it in position.

The speaker is now in place and the lighting connection bar has been refitted as it was originally. The two plastic mounts hold the speaker in place.

Next, the speaker needs connecting to the decoder. You can do this by joining the wires from the decoder to those from the speaker or, as we have done here, by removing the actory speaker wires from the decoder and resoldering those from the new speaker to the tabs on the decoder.

At the end of the decoder we removed the red, white and black stay alive wires from the decoder to allow those on the capacitor board to be soldered directly to the decoder. This avoids extra joints, but if you don’t want to solder on a decoder board it can be done by twisting the matching colour wires together and covering the joints with heatshrink insulation.

The 21-pin decoder can now be pushed onto the locomotive’s 21-pin socket. When removing the socket blank, be careful not to bend the pins.

The Sound installation is now complete. The stay alive pack fits neatly in the area above the bogie at the NO.2 end of the locomotive.

As a final step before refitting the body, Black Tack was added at all four corners of the speaker to keep it firmly fixed in place.

After refitting the body, we noticed a couple of paint flakes from the lower cab handrails. We touched them in with Humbrol Matt White acrylic (NO. 34) to prepare the model for service. 66783 is now ready for the rails.

Above: Hattons has created 37 different livery choices for its ‘OO’ gauge Class 66 and through clever use of CV programming the Legomanbiffo decoder allows horn and spirax valve sounds to be tailored to suit different batches of the EMD Co-Co diesel. This is 66783 at the head of a container train.