Portal Clearance

@Trainlover160 posted:

Have any of you ever had to  trim the sides of the portals to make sure that there's clearance?

The answer is "yes." Use your longest engine and passenger car to check for clearance. The portal above your Blue Comet looks like it's urethane and can be trimmed. The smaller the curve radius, the more of a clearance issue it creates, so it may help to use a larger radius track piece under the portal. Depending on the engine or car, it may also help to offset the portal slightly so that it is not precisely centered over the middle rail. If you do that, experiment with the engine and passenger car to find the best portal position.

MELGAR

I've seen posts here on the Forum where people have either trimmed portal sides or made their own to provide clearance when used in tight curves with big Locos.  Alternatively, wider curves, or even better, straights sections through the portal might provide the needed side clearance.

My suggestion is to plan portal clearance for the future.  The is based on my lesson learned.   Even though you may not be planning on a Big Boy or such today, these steamers can have significant overhang and your interests may change in the future.  If you make sure the big steamers clear you are good to go forever (hopefully).

Didn't intend to lesson anyone else's ideas.    My intend was not to suggest HOW to accommodate clearance, just to considering PLANNING for additional clearance if desires should change in the future.

Thank you everyone for your input. My longest passenger car is 18", my mainline radius is O-84. The radius on upper level is O54. That radius has no portals

My plan is to run O and STD Tinplate with hirail once in a while

I would not be buying a Big Boy as I do not feel it would look right on my small layout of 8 x 12. I will let the guys with huge layouts run those. I am also content running 15" and 18" passenger cars over the 21".

Will keep you posted.

Thanks Again,

Joe Gozzo

Airplane movie line.

Peter Graves as pilot on the radio to the tower:

Do we have clearance, Clarance ?

Rodger, Roger!

I had to trim back the side of a portal to accommodate some 18 inch passenger cars.   Of course that was on a 42 inch curve radius.

In addition to the fine advice already given by MELGAR, Steve, and Shorling:  If you think that you might one day purchase a GG1 and running it with pantographs in upward position you may want to consider raising your portals to accommodate the upward position.  If you don't already have a GG1, and are considering owning one in the future, you can always give a shout out here on the Forum for measurement of total height with pantograph raised.  This height may vary from manufacture to manufacturer.  When I first installed my portals I never dreamed of owning a GG1.  Once I purchased a GG1 and decided that I wanted to run it with raised pantographs ( and one day install fake catenary ) I had to go back and raise the portals about an inch or so and even cut the top of one portal.   That was quite a job!  LOL!  

Good luck on your layout!  

Patrick,

On the Northeast Corridor, the catenary wire height is reduced in tunnels and the pantograph is not fully extended, so the portal height, which is about 5 inches at model scale (20 feet full scale) should be sufficient without raising the portal.  On an MTH Premier GG-1, the retracted pantograph height is about 3-3/4 inches above the rail (15 feet full scale).

MELGAR

Yes

Due to an H8 Allegheny articulated engine I’ve not trimmed but increased the opening width.

The primary issue I have is that my portals were placed at the 042 radius curves.  I did not have any alternative.  I had to purchase a second portal and trim in two one portal then splice in an added piece.

I think the H8 on an O42 curve will cut a wide swath!

A pantagraph when in use, is retained in a mid range height by the over head wire.   Never fully raised as most models are pictured.  In subway terminal situations the pantagraph seems to be almost fully collapsed due to low ceiling.

So the use of a fine wire hook somewhat like a Christmas tree ball hook hanger retaining the pan at a reduced height would be appropriate.

Restrained pantagraph heights will assist the model RR in portal clearance and overhead bridge considerations.