Fun with Helpers...

[wm3798]

I've been working on the helix to get in and out of west staging, which ended up being a bit steeper than I would have liked (about 2.9%!)  So I've been testing various train lengths with some helpers.


Our faithful pair of FA-2's wait patiently in the pocket for the end of the train to pass on its way up the helix.


301's coupler is cocked to get a good angle on the caboose's coupler without fully engaging it.


Carefully, the FA's put a shoulder to the rear of the train, keeping the slack in so the engines on the point can handle the 2.9% grade.  Both sets of engines are operated from the same throttle, but I toggle back and forth between the two consist addresses to control each lashup independently of the other.




As the lead power crests the hill and heads out onto the main, the helpers slow down and release the caboose on the fly.  They then glide back down the hill and into the pocket below decks, ready for the next train to be released from west staging.

So far I've successfully tested this method on a 36 car coal train, a 30 car mixed freight, and tonight, I ran up a string of auto racks and 85' hi-cubes.  I've found that it's best to have body mounted couplers on the rearward cars, especially the caboose, as this keeps the trucks from going all caddywumpus like they do with truck mounted talgos.

Also, while I was hanging around the helix, I started doing some preliminary track layout for the west yard throat.


I was able to work out the whole shebang with the turnouts I had on hand, and the only compromise I had to make is the three #5's I used there in front of the car shops.  I had a choice to either use #7's and be stuck with 12"r transition curves, or #5's and stick to my minimum 15"r.  I figure with low switching speeds and the slight down grade from the drill track to the class bowls, that the shorter turnouts wouldn't have a big impact.

I will end up with a lot of surplus #7 rights, but I'll need more #7 lefts to build the east end of the yard...  If anyone has a need to swap, I'm all ears.  But there's no immediate hurry for that.

This weekend we'll be building the temporary connection to get from North Jct. over to the above panel, about 14' of track altogether.  Hopefully by the time day is done, we'll be able to run a train all the way from west staging to east staging...  

And for Ed's reference, the A/D tracks will be in the front, there will be 8 class tracks, minimally 4' long each, and the east throat will be in front of the round house.  It looks like I'll have room to model more of the engine shop complex, and this makes my palms sweaty with anticipation...  Here's the general plan I'm following, courtesy of the White River and Northern...



Note that I've abandoned the idea of the "red" yard outside the mains, and reconfigured the throats based on the track I have on hand.  Tomorrow I'll do the necessary tidying up and screening under the helix, and get this panel cut and installed in preparation for Sunday's festivities.

Lee

[tehachapifan]

Cool!

I've never had any luck with running helpers. One studder with the helpers or the lead locos and the train ends up on the ground. :'(

Russ

[kiwi_bnsf]

Hi Lee,

Great description of helper operations! It gives me some hope, as I am planning to run 25-30 car trains with up to five units on a helix with 2.5% grades. I guess I will need to invest some time in body mounting at least enough cars for the rear of trains.

One question - what radii are the inside and outside tracks of your helix?

Cheers

Tim

[conrail98]

Also, while I was hanging around the helix, I started doing some preliminary track layout for the west yard throat.

In looking at the plan by DKS and what you are laying out here Lee, are you putting the car shop between the A/D lead and the class tracks? Also, the more I operate on a couple of layouts, the more inclined I am to put the A/D tracks at the front of my yard. Guess I know what I'll be tinkering with on my plan over the next few days. Just so I understand the yard itself, do all trains stop here and drop power? Thanks,

Phil

[wm3798]

Phil,
I relocated the car shop to the void between the yard ladder at the main line curve to the outside.  This allows me to nick the plywood back to open up more of a view of the helix underneath.

Kiwi:  The outside track radius in the twist is 16", the inside about 14.5"  The inner loop is the down-bound route.

It is critical that the helper units be smooth runners.  They'll get their wheels cleaned regularly, I can assure you!

Lee

[conrail98]

Thanks Lee, that's what I figured. I'll also be interested in learning more about how you handle helpers as I'm going to need them on my layout also. In addition to what you've said about the helper units themselves, I've also read that you really need properly weighted cars, whether empty or not, to really make sure you are ok with the extra locomotives and that you want some resistance in the wheel-sets, i.e., free wheeling is not your friend. I'll have to find the post I read on that, I know it's somewhere in my RSS feeds,

Phil

[mark dance]

We just introduced pushers up both sides of Farron Hill on the C&W.  About 3 scale mile push Westbound (including 2.5 turns on a 18" radius helix) and 1.5 scale miles eastbound.  It has added a whole new dimension to the layout: train handling!

I have started upgrading all the digitrax throttles to duplexing radio as I was concerned about the line of sight IR going "blind" at an inopportune moment.

I have also added an ounce or so of lead to all the empty 33' hoppers.





Great to see more helper operations!

md

[wm3798]

I'll definitely be adding weight to those damn MT hoppers, they're light as a feather and wreak havoc pretty much anywhere they go.  The body mounts I've done on the Atlas hoppers work just fine.  So far I'm finding that a light touch with the throttle is as important as car weights and couplers, though.  I'm sure that once the helix is closed up, I'll need to rely more on physics than finesse!

Lee

[mark dance]

The C&W crews pushing and leading through the helix have one instruction: "don't touch the throttles!"

The desire to mess with things is high even though the train can be tracked by viewing with a mirror.  Once the train is underway and into the helix we have found it best to just leave it to its own devices.  The 25% of the westbound push in the helix is a nice stable environment with constant grade and constant curvature unlike the visible portion of the push.

Now that the cars have been weighted properly any derailments have occurred in the visible areas of the layout mostly because of crews not coordinating their speeds well, especially when coming to a halt.

md

[SebastianLee]

I'm glad someone got helper service to work out. I never could get reliable service, especially with guest runners. I ended up ovaling my helix by adding about a foot of straight run on each side to lower the slope.

[John]

Nothing wrong with helpers .. but i think doing it in a helix buried under scenery is a disaster waiting to happen .. I will be the first in line to tell you "I told you so"

[mark dance]

I'll guess we will see...so far so good.  And it certainly adds to the excitement

I should note that there isn't anywhere for derailed trains to go as the 2 helix turns are padded on the inside edge which in turn is 3" away from the centerline of the track.  I think the worst that can happen in a stringline is the trains are pulled up against the padded retainer.  The helix is easily accessible from the inside as well with a 30" inside diameter, and open at the top so it is reasonably comfortable to get into and work in if derailments do happen...perhaps this is a difference?

The risk is low - just embarrassing - and it is a hobby after all. As I mentioned, when derailments have occur ed it has been on the 85% of the pusher grades where operators have messed things up.

Just before Christmas I had two Prototype Engineers visit for the first time and push a train up a grade between them.  Worked beautifully and definitely worth the price of admission!  Maybe an example of facts shooting down theory??

We will see...

md

[Bob Bufkin]

I was thinking the same as John.   Whatever you do, don't ever put me on the helper.  You know how hogfooted I am with a throttle

[conrail98]

Lee, I've been looking at the proposed plan for the yard and there is one major flaw in it. You can't get to the A/D tracks without disrupting either switching lead. This is going to cause major pain points for whoever is going to operate the yard,

Phil

[davefoxx]

Nothing wrong with helpers .. but i think doing it in a helix buried under scenery is a disaster waiting to happen .. I will be the first in line to tell you "I told you so"

HAHA!  I get to be the first to put 'em on the floor.

DFF