The N27 built SS7D's were marketed under the peculiarly named Orangutan models. This was N27's third plastic bodied model and their latest offering at the time of writing (January 2016). These locomotives are very popular with Chinese railway fans and N27 have done a very good job of recreating them. Two runs were released in quick succession with eight road numbers including special locomotive #0631, an out of sequence number in the SS7D which took over the coveted title of "Steel Man Iron Horse" (at least that's the mechanical translation!) from DF4B 0631. Unlike most other named locomotives, 0631 appears to be devoid of any decorations from the photos I've seen, save for some banners in the windshield. The packaging is solid, which is nice, however this is one of these models where you need to be careful which way it sits in the plastic clam shell case, as the wrong direction will see damage to one of the roof insulators. It should also be noted that there are small foam tabs inside said clam shell which mess up the paint by leaving some sort of adhesive residue behind on the model.
These are very nicely detailed locomotives. The details cast into the body are excellent. The paint work is very good, however there are some minor imperfections, chiefly around where the blue paint work meets the silver. There is some extremely minor overspray in areas, the most obvious being around the front of the locomotive along the top of the bottom blue line. My example is #0002 which I chose after I photographed it back in 2006. One prototypical error I've found is the cab side number plates which are the stencilled painted on style that most of the class wore, however 0002 has separate side cab number plates.
Roof details are very good and the pantographs look pretty good, aside from the rear most tripod mount which is a very oversized large plastic cylinder that looks rather ungainly. I suspect this is to allow a wire to the pantograph for electrical pick up, however it is rather ungainly. Air conditioners look fantastic, as do the windshield wipers, brass air horns with incredibly fine pneumatic lines. The bogies are very beautiful with very intricate brass step ladders and an impressive depth. There are some extra details to be added by the owner being side mirrors, antennae and bogie linkages.
My model runs a little buzzy out of the box, which improves slightly at higher speeds. I believe a gearbox lubrication will solve the problem. It weighs just over 600 grams and the motor is strong. Locomotive is 4 axle drive with a free floating unpowered centre bogie.
Power is ferried from the rails (or pantograph and rail if you wish) via a circuit board to the motor and the lighting system. At the time of writing, I have not converted my example to run on DCC, nor have I opened it up. I am presuming like other Chinese models the board will accept an 8-pin decoder. The selector switch to convert electrical pickup between the pantograph or wheels is under the brake resistors (centre most large box on the roof). The lighting system is good. Lights are directional with a whiteish blue main headlight and yellow marker lights in forward direction and red in reverse.
The couplers . For those who like Kadee couplers, they can be easily replaced with #56/156's).
One of the coolest electrical locomotives is now in model form. They are still fairly obtainable at the time of writing and highly recommended for modellers of modern Chinese railways.