This article is not designed to cover all of the F-units that Burlington Northern owns but only two particular units that I chose to model. There are several reasons why I selected these units to model. First, I had good photographs of them from both sides. Secondly, I thought that they would be fairly easy to model as the plastic bodies were close to the prototype. In the case of No. 676, this wasn't exactly the case as I mistook it for an F7 when I started the project only to discover that it was a late model F3; the only visible difference being the dynamic brake grids which aren't easily seen from ground level.
Burlington Northern No. 676 was built by the Electro Motive Division of General Motors in October of 1948 for the Great Northern Railway as their No. 306A. GN referred to them as F5's since they were F3's in F7 carbodies. The only distinguishing feature on the outside was the F3 style dynamic brake screens on the roof; they were replaced on the F7's by a 36" fan. No. 676 is the last one of its class still on the roster although there are four other F3A's and one F3B still active as this is written. BN F9A No. 814 was built by EMD in September of 1954 for the Northern Pacific Railway as their No. 7000D. It is one of 21 F9A's of its class still on the roster although there are an additional 16 ex-passenger F9A's and 36 F9B's still active. The outlook for F-units on the Burlington Northern looks bright as they stopped retiring them several years ago and have chosen to rebuild the remaining F-units on the roster. This should insure their presence on the roster for many years to come. For further information on the BN F-units, consult the BN Annual books.
BN F3A No. 676 is easily constructed using the Athearn F3A body and mechanism plus the addition of various detailing parts. The major modification to be made is to change the dynamic brake cooling fan. First, the cast on 36" fan should be removed with a file and sanded smooth, be careful not to remove the rivets on the surrounding panel.
Next, two holes should be cut in the location where the fan was removed. The holes are .650" long by .200" wide with .200" between the holes and centered on the panel. The underside of the holes should be undercut around the edges so that the screen will fit closer to the surface. Kemtron screen should be cut to fit and epoxied to the under side of the holes. A border of .010" styrene should be embossed with rivets and cemented around the edge of the holes and cutting the ends at a 450 angle to fit each other. See Figure 1. Next, the cast on steam generator and lift rings should be removed from the roof and sanded smooth being careful not to damage the rivets. The four waterfill hatches should be removed and sanded smooth. I failed to notice that they should be removed until I was getting ready to decal so they were incorrectly left on my model (one can be seen under the word "Burlington"). The nose-door light should be filled in with body putty and sanded smooth.
The position of the horns on the roof has to be changed to make room for the cooling coils. Fill in the rear hole that each air horn was mounted in with putty and drill a new one in front of the forward hole to accept the horn mounting studs. The cooling coils are made from .020" brass wire and bent to the pattern in Figure 1. It then should be soldered to .015" brass wire and attached to the roof behind the horns. The roof railings around the horns are made from .015" brass wire and are .500" long, positioning according to Figure 1 . The roof lift rings were replaced with those made by Detail Associates, No. LR 1101.
The side skirts were modified following photographs, cutting and filing to the correct shapes. The grab irons on the nose were positioned following photographs, using Detail Associates No. SY 2201, and bending others from .013" brass wire. The railings on the side were made from .015" brass wire. The door covering the MU receptacles was simulated by scribing a door on the nose next to the light (see photograph). The nose door handle was made from a small piece of brass wire. The coupler lift bar was made from .015" brass wire following photographs and was mounted in Kemtron lifting eyes. Windshield wipers were made from .010" brass wire. MU hoses by Detail Associates, No. MU 1508, were applied front and rear. The marker lights were drilled out to accept jewels, Detail Associates No. JW 1703.
Burlington Northern F9A No. 814 was made from a Bachman F9A body mounted on an Athearn frame. The roof detail is correct for the ex-NP units except that the cooling coil has to be added using .020" brass wire following the diagram in Figure 2. Cross pieces of .015" brass wire are soldered to the coil and attached to the roof. The steam generator detail is filed off and sanded smooth. The horns are removed and the holes filled with body putty. An Alco Models three-chime horn is attached to the roof on the right hand side. The number boards on the nose were replaced with the Athearn PA type. Nose lifting lugs, Detail Associates No. LR 1102, were applied to the nose. Both nose lights are left on the nose. The rest of the detail is the same as BN No. 676. Be sure to check the photographs so that you don't forget to do something.
Before painting, both models should be throughly washed. The grilles are painted with Aluminum and, when throughly dry, are masked. The noses are then painted white and, when they are throughly dry, they are masked with tape a scale 12" wide with 12" spacing; follow the photographs for correct location. The noses and sides are then painted BN green. When dry, the green is masked off using the photographs as a guide. The roofs, ends, and underframe, including the pilot, side skirts, and trucks, are all painted black. The grills were weathered with thin-downed grimy black, wiping on a small amount and then quickly wiping it off before it can dry. This leaves a small amount of black in the crevices. Micro Scale decals were applied and a flat coat was sprayed over the entire model. They were then lightly weathered with earth colors. The windshields and jewels were then applied to complete the models.