Simpson 900 in N…

Alongside the Englewood SW1200 duo I managed to get a little distracted resulting in a small diversion, the Simpson Lumber SW900…

 

The prototype differs from the SW1200 that were fitted with dynamic brakes, in the fact that the smaller prime mover meant the dynamic brake equipment could be placed within the profile of the hood, so unlike the SW1200 with the raised section, the SW900 has a much cleaner outline…

Simpson Timber Company #900 pictured here in 1999, photo Alan Sewell, with permission.

STC #900, 1999, photo Alan Sewell.

EMD SW900 #900 in 1999, photo Alan Sewell.

The above photos by Alan, who kindly emailed them over, show the prototype in 1999. I find it strange that she runs on standard switcher trucks rather than the Flexicoils, as with the dynamic brakes fitted she is definitely more of a road unit…

Alan says in the comments below:

“I think the Canfor units on Flexcoils were the exception. All the logging SW’s I have seen rode on AAR switcher trucks that includes all the Simpson lokeys, the Weyerhaeuser Longview “motors” and the units on Coos Bay, Kosmos etc. Manyof these had runs in excess of 40 miles from the woods to the dump. I don’t know why STC ordered dynamics. They had some steep grades and did not MU their lokeys until the mid-1980’s, so perhaps a safety feature or some good salesmanship by EMD!!”

To model the prototype I designed a sourced a 3D printed replacement section of hood, basically cutting away the tapered section above the handrail in front of the cab. I smoothed the doors below the handrail to allow a set of etched grills to be fitted, above and below the moulded handrail. The SW900 only has one exhaust stack to the second was cut away and the hole filled and smoothed.

At each end I modified the handrails to allow fitting of MU socket and non working ditch lights, as well as smoothing the foot boards and replacing with some styrene. The prototype also had side handrails so these have been drawn up and etched in brass at the same time as the grills. These were left off until the end, being blackened rather than painted. One end side handrail is missing, eaten by the carpet monster (this thing is tiny) and I need to look at how best to do sunshades, on this and the other units.

Painting in Humbrol enamels was followed by fitting some custom decals I designed and had printed. The finished model has been weathered, to tone all the different parts together. Although I could pick out the end handerails in white and add jewels to the ditch lights, I’m generally happy with the model and it scratched an itch that otherwise might have festered and resulted in a H0 diversion, which would have been more expensive for sure! As it is, the Simpson model should see service in whatever N scale logging layout develops in time.

Although a personal model, this shows my approach combining both CAD and custom designed and produced parts with traditional model making and  scratch building methods. If you’ve got a prototype that requires some modification of a ready to run model whether it’s Australian, British, European or whatever, get in touch for a personal proposal. Until next time…

Edited to include photos submitted by Alan Sewell.