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Following the success of our Trojan range it was soon realised
that the four motors had ample power to spare and it was only
adhesion to the rails, which limited the power output.
There were two options available for transferring more power to
the rails -
1. More Weight
2. More wheels
Option 1 was ruled out as more weight on just a
pair of axles would affect handling, increased wear on components
and possibly lead to track damage.
Option 2 was the preferred
option. Plans for an 0-6-0 were drawn up but the required
longer wheelbase would have exclude it from
running on our track.
By opting for a bogie design more of this surplus power could be
transferred to the rails. The short wheelbase of each bogie also
had the added advantage of allowing the Hercules to easily cruise
around tight corners, which are often found in garden railways.
The only possible down side was the gamble of had we gone too far
and produced a loco which would draw too much on the motors and
lead to the motors overheating.
The Trojan incorporates motor mounts, which are
held in the vertical position on the chassis. With bogies we had
to set about designing whole new mounts to allow the wheel sets
to move and provide suspension. The unique design we came up with
incorporates a system where the motors are part suspended by a
5mm pin under the bogie cross bar. In using this design the
un-sprung weight of the motors is greatly reduced to less than
half the weight of the motor. The design also facilitates easy
removal of the wheel sets and motors should you ever need to
replace parts.
Early January 2003 saw the
completion of Hercules No.1. Running without cranks it soon
became clear on early tests that the power output was far better
than the Trojan. It also highlighted the smooth running of the
loco which glided around our track. Initial running and loading
appeared to have no effect on the heating of the motors.
Some of our early testing included -
- 1 in 10 incline - two adults from standing
start on steel rail
- 1 in 20 incline six-foot radius - two
adults from standing start.
- 9 adults on five coaches around a club
track including a 1in 40 standing start
Confident that the power aspect was a big
selling point we built a display ramp of 1 in 10 and took No. 1
to the Harrogate show. The ramp was made from angle iron, which
has less grip than rail section, but it still made quite an
impact. One gentleman suggested that his 18 stone would be too
much for the engine. After a slippery start it pulled the
gentleman up with
little effort. The Hercules is not based on any locomotive in
particular but rather a hybrid of the Trojan loco. Its main
function is to be able to house two standard sized car batteries
(which provide enough power for a good days
running) under the bonnets.
While I have been told Hercules looks like specific locos, this
is more by chance than design. The bonnet, cab profile, doors and
front grill are from the Trojan, the roof from the industrial cab
meaning that the body work only has three new parts.
The bogies incorporate similar running gear to the Trojan
and in fact share the same wheel sets, axle boxes, springs, axle
box guides and bearings.
Design amendments from prototype
* Removal of ROR logo from bogie cross frame -
hidden by motors
* Cross bar thinned to stop clashing with motor bush hubs
* Large holes in deck over bogie bolts to allow acces and room to
bouble lock the bogies
* Supply of vertical dashboard plate
* Quick release bogie plugs
* Battery tray end plates ready cut
  
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