That would be the standard Stewart drive (not Kato) with Buehler motors. I have found these to be excellent runners in reguard to smoothness, endurance, and pulling power. They are very easy to service and install decoders and sound in. I own over 100 of them and can highly recommend them.
The bodies are lacking the exterior detail of the Genesis and Front Range models. I’ve been considering moving some of my Genesis (highliner) shells onto these drives.
It would almost certainly have the Stewart drive system. I have some of the F units with the Stewart drive and they run very well. Smooth quiet and good pullers.
Big thumbs up i just got two f unit ab sets they out perform everything i have Atlas, p2k, athearn they are so quiet its hard to hear them run and great pullers. The details as mentioned may not be as good as Atlas,P2k but for me the running ability is what i like i can always add details.
All the Stewart diesels I own or have seen operating, range from very good to outstanding for running qualities. The F series are outstanding, the absolute best runners in my modest diesel fleet which includes Atlas, LifeLike P2K, and Bachmann Spectrum. The VO switcher models are also outstanding, very nearly as good as the F series and easily #2 for running qualities in my diesel fleet. Stewart AS-16 does not perform to the same level - “merely” very good and not as good as some of my Atlas.
Beware of generalizations about Stewart; the drives differ somewhat in quality depending on the diesel being modeled and the run, as does the shell detail and the paint / finish job. The F series are a bit lacking in shell detail but, being F’s, its quite easy to add a few details and upgrade the overall appearance without a significant extra investment. Another option is to purchase an Intermountain F shell and finish and paint it to match your prototype.
When buying second hand (e.g. E-Bay or train shows), one thing you need to watch for is Athearn mechanisms. In its earliest days (over 20 years ago now) Stewart started with custom paint jobs on Athearn diesels.
All the Stewart diesels I own or have seen operating, range from very good to outstanding for running qualities. The F series are outstanding, the absolute best runners in my modest diesel fleet which includes Atlas, LifeLike P2K, and Bachmann Spectrum. The VO switcher models are also outstanding, very nearly as good as the F series and easily #2 for running qualities in my diesel fleet. Stewart AS-16 does not perform to the same level - “merely” very good and not as good as some of my Atlas.
Beware of generalizations about Stewart; the drives differ somewhat in quality depending on the diesel being modeled and the run, as does the shell detail and the paint / finish job. The F series are a bit lacking in shell detail but, being F’s, its quite easy to add a few details and upgrade the overall appearance without a significant extra investment. Another option is to purchase an Intermountain F shell and finish and paint it to match your prototype.
When buying second hand (e.g. E-Bay or train shows), one thing you need to watch for is Athearn mechanisms. In its earliest days (over 20 years ago now) Stewart started with custom paint jobs on Athearn diesels.
I don’t know that one can make that blanket statement. I have had pulling power issues with my Genesis. The F3 ABBA set I got with the extended Superchief set couldn’t pull it up the first hill out of the yard. I simply replaced them with Stewarts and had no problems. I am going to do some experimenting to see if it is something simple wrong with just that set of units or truely an issue with the models.
The point is they will not be disappoint you in how they run.
It comes with all the handrails, grab irons, MU hoses and brass windshield wipers. I substituted the included wipers for A Line units because they looked better. I also added a firecracker antenna. The rest of the job was Dull Cote, weathering pastels and a single LED powered fiber optic class light installation.