I just completed the mountain loop of my 15'x25' layout. It is an oval along the perimeter of the layout with a 30 degree crossing at the mountain top allowing it to circle the mountain before descending back down. The loop has a 12" vertical climb, 2% grade, with Atlas O-72 and O-81 curves.
I first tried my Weaver TMCC Brass Little Joe with nine heavyweight passenger cars and I was dismayed at it's sluggish performance barely making it up the mountain. More alarming, its amperage draw popped the breaker on my Z-1000 brick. I switched to my Z-4000 to monitor the current. When it reached 9 Amps, I quickly shut it down. It also had erratic speed which sent me down the rabbit hole of track cleaning, rail joiner tightening, checking for voltage drops, and finally adding another power drop, but performance did not improve.
At that point I tested other locomotives and fortunately they had much better performance. So I thought I would collect some data and share the good, the bad, and the ugly.
I tested 3 locomotives with a heavy load of ten 18" Heavyweight Passenger cars from Lionel, K-line and GGD. All had incandescent lighting. Power was a Z-4000 set at 18 Volts through a TIU. Control was both DCS and Legacy. Amps are from the Z-4000 display (Yes, I know . . .) Here is the current draw in Amps for the 3 locomotives. To show the peak motor current going uphill, I subtracted out the current draw from the passenger cars and Idle Loco electronics and lighting. (Motor Peak Amps = Up 2% grade - Idle)
Locomotives
Lionel 6-24507 Milwaukee E6 A powered-A dummy pair w/TMCC
MTH 20-5607-1 EP-2 Bipolar w/PS2
Weaver G1715LP Brass Little Joe upgraded to Cruise Commander
Locomotive | Idle | Up 2% grade | Down 2% grade | Loco Peak Amps |
Locomotive Only | ||||
Lionel 6 Powered A Dummy A TMCC | 3.2 | 3.6 | 3.3 | 0.4 |
MTH Bipolar PS2 | 2.9 | 3.1 | 2.9 | 0.2 |
Weaver Little Joe | 2.9 | 4.7 | 4.0 | 1.8 |
Locomotive/10 cars | ||||
Lionel 6 Powered A Dummy A TMCC^ | 3.2 | 5.1 | 3.6 | 1.9 |
MTH Bipolar PS2 | 2.9 | 4.2 | 3.2 | 1.3 |
Weaver Little Joe | 2.9 | 8.1* | 4.8 | 5.2 |
^E6 has the extra weight of the dummy unit
*Peak Amps while moving before stalling
So clearly the Little Joe is not going to pull a long train. I did check for any binding in the trucks, nothing obvious. Even running alone, its current draw is way out of line with the others. It is a heavy beast. So what do you think? Is this the expected performance of the Little Joe, or do I need to take it apart and evaluate the drive train? (I'm thinking yes . . .)
Bob
