SS4/B/C/G Class Bo-Bo+Bo-Bo
The SS4 electric 25kV locomotives comprise of two units permanently coupled to each other back to back. They are used on heavy freight trains over much of the country, with major concentrations at Baoji, Shanghai, Beijing and Shenyang. Four locomotive factories (Datong, Dalian, Zhuzhou and Ziyang) have manufactured nearly 1000 locomotives sinch production began in 1985. Five liveries exist. The earliest examples bore a predominantly white livery with a large blue stripe over the side louvres and a smaller stripe along the bottom edge of the body as well as a small orange stripe under the cab windows. This was soon superseded by a dark blue/cream livery. These early units had five narrow porthole windows above the louvres - later type had six. The early SS4's are now being withdrawn, but a number are still operating out of Shanghai and Baoji. The later versions have a light blue body with cream cab and narrow stripe and make up most of the class. There were also a couple of prototype color schemes on some improved variants, green, blue and yellow and silver, red and blue, although I'm not sure if these survived much beyond the testing phase. They have a weight of 184 tonnes and over 8,500 horse power and held the title as China's most powerful locomotives for just over two decades.
The SS4's have been a very long waited electric locomotive for those following modern day Chinese railways. These are very elegant locomotives, and Bachmann have done an excellent job in recreating them. Bachmann have made four types of SS4 (SS4, SS4B, SS4C, SS4G) with their model, but asides from the livery, there is little else to distinguish the different types.
Bachmann China have used a good quality two piece cardboard box with two partitions. Each unit of the locomotive is stored in a plastic clamshell type with a plastic sleeve. There is a pair of plastic pieces to help support the model and various pieces of soft plastic sheet to protect the paint work.
These were probably the most highly detailed models bachmann released, until the arrival of the legendary SS7C. Everything is super small, and delicate looking, but they can be handled fairly well without pieces falling off. The paint work is excellent as we've come to expect, asides from some extremely minor quality control issues on a few of my examples. Some of the lining is a little fuzzy also, but not overly noticeable. The lettering is razor sharp, and the road number specific detailing is very impressive. The dark blue variant has six porthole windows per side per unit rather than the five, however I see this as more of a compromise to save tooling costs, rather than an oversight. I would much rather have this color scheme in the line up rather than not! There is a bag of small parts which need installing - mainly bogie parts, antennas, GPS equipment, etc. Many of these are atom sized, and will require a lot of patience and concentration to successfully apply.
The SS4's are pretty nicely weighted. If these were single units, then it would probably be a different story. Both units are powered and connected via a drawbar with a locking hook. I'm not sure about the strength of the drawbar (and God help me if it breaks as its a very complicated precision part), only time will tell. The operation is flawless, with a similar system to Bachmann's passenger cars to ensure that both units sit almost touching each other around curves of just about any radius. They both operate (and should be operated as a double unit according to the prototype police), however the A unit can be run separately (the B unit cannot run with out the A). Thankfully both units are motorized - a huge relief, after the underpowered DF11G's. If there was one thing regarding the performance of the locomotives, it would have to be the speed, in which all my units run very slow - approximately 60kph running light engine and decreases depending on the length of the train.
While I've been a bit worried about some of the trends coming from Bachmann China recently, there are no such worries with these models. The mechanics are beautifully engineered, everything fits and performs exceptionally well. The pantograph design is no longer a clip in job (that after activating a few times would cause paint loss to the pantographs), there is instead a horizontally placed hook that the pantograph slides onto. The spoked wheels are made of steel, like the ND2 diesels which translates as better adhesion, longevity and better looks - especially if you're machining down those flanges (old habits die hard!).
Electricity is moved around the engine via a PC board and wires. They can be operated from wheels or pantographs/wheels via a selector switch on the PC board. The lighting is directional.
There is enough room inside the shell to accept most HO scale sized decoders. As per standard Bachmann practice, they have an 8 pin socket to accept any NMRA 8 pin decoder. There are also speaker holes to accomodate a sound card.
I've not yet converted my couplers, but they will accept long shank (#56/156) Kadee couplers and most likely standard #58/158's. Installation looks to be very simple - just unscrew the coupler plate, and replace. As a side note, the Bachmann EZ mate knuckles on this version appear to be a new design - although the same basic principle and materials from the previous design/s. The major notable difference is the coupler head size, which look quite a bit better, however I still prefer and trust metal knuckles, so these will be retrofitted in the near future.