Ever since I
received the boiler, I have been working on getting the suspension and
weight distribution set correctly. The problem I have run into is that
most of the weight of the boiler is on the rear truck. I thought about
installing a "Hanson" booster (chain drive) to increase the
tractive force, but I thought I should try to fix the problem at the
source and then see if I still need to install a booster.
I have been
corresponding with "Phill the Suspension Man" from down under. He knows
his stuff. Gave me some great ideas to try. He suggested ways to
shift the weight to the drivers and to break up the equalization of the
wheel groups along with the proper order of doing these things. I have
summarized the tasks and the order that they were performed.
1) Group Wheels
a. Front Truck
& Front 2 Drivers
b. Rear Truck
& Rear 2 Drivers
plans called for all drivers and rear truck to be equalized together. To
minimize the amount of work to do this, I "pinned" the equalizers
between the 2nd and 3rd driver. This effectively froze it in place so
the motion between the 2nd & 3rd drivers were isolated.
2) Adjust Journal
a. Front Group
at #2 axle
b. Rear Group
at #3 Axle
Rear Truck Front Axle
Rear Truck Rear Axle
i. Do one
axle at a time (both journals/springs) then check with weight on
blocks under the ends of the frame when taking the weight (boiler) off
the wheels so you do not have to reset the springs when putting the
boiler back on.
at one end and work your way along
hangers must be the same length within wheel groups (except for the
first and last hangers of a group)
engine must be at operating weight (boiler with water)
Springs must be parallel with the frame
increase travel of the journal, reduce number of leafs. In turn, to
minimize travel, put more leafs in.
3) Weigh Wheel
Truck; Front Axle
Truck, Rear Axle
c: Driver Axle
d. Driver Axle
e. Driver Axle
f. Driver Axle
g. Rear Truck;
h. Rear Truck;
Weight on Axles
increase weight on an axle, move pivot point for the spring lever
arm to that axle
decrease weight on an axle, move the pivot point for the spring
lever arm away from that axle
the length of the hangers does nothing to alter the weight on the axles
In order to
implement these changes, modifications were needed to the number of leaf
springs, pivot points, etc. I
making 32 spring hangers for my 4-8-4, and then found out the hangers
were no longer the correct length due to the increased weight during
construction, I quickly realized that I needed another way to adjust the
spring tensions on each of the drivers. Now the solution that I used
will definitely make the purists "cringe", but the time saved and the
performance obtained was well worth it for me. Besides, they can
barely be seen when done.
Below are pictures and drawings of the hangers
and pivots that allow 3/32" adjustments on each of the drivers. Over an
inch of height can be taken up or down without having to make new
hangers each time. In the pictures, the hangers look like they are
angled toward the axle, which is not the case. This is due to the angle
that the picture was taken. They are in fact straight up and down.
I also needed to
find a method for weighting the wheels (all 16). At first I was going
to make a 16 foot rail section with scales in the middle. The plan was
to role the engine over the scales and read the weight on each pair of
wheels. Making this would take a better part of the day, so I came up
with another solution that may not be as accurate but it does give me
relative weights of the wheels. Basically, I machined a 1/4" (or so)
plate of steel (3" x 6") with "fingers" to go between the rail and the
bottom of the wheel. A round head screw was added to provide a pivot.
Here's a drawing to see what I am talking about.
The fingers were
pushed in between the rail and the wheel. I attached a scale on one end
and a place to put my foot on the other. To get the proper weight
reading I placed a level on the plate, then used my foot to pull down
the plate until it was level. Then I recorded the weight. It's best to
look at the pictures to clarify this.
This setup let me
leave the engine on the stand, which also saved time (by the way, you
need to use the engine stand or equivalent angle iron for this to
After all was said
and done, I believe I came up with an acceptable setup. Glad that I
made the adjustable spring hangers. Saved my butt a lot of time.
I modified the
rear truck pilot to correct some height problems also.
Here's the engine
properly balanced and ready for the next step
Again, I would
like to thank Phill for his help with this.