Wednesday, 27 December 2017

Demand Based Car Flow - Model Fleet Part 2 - The Total Number

A few weeks ago I used a demand based car flow system to begin  determining my freight car fleet. The exercise highlighted that daily trains departing staging would consist of 6 or 7 car lengths.

I plan to run my layout on my own most of the time and want to be able to enter the shed and run a train. To start out I envisage 3 trains daily crossing the layout, local freight, passenger and dedicated log train, with the the options of adding an extra freight when I have 2 operators.

This would mean I need the option to have staging for 4 trains at Vancouver end of the layout and also 2 free tracks to run around and somewhere to turn locomotives. i haven't determined if i will use a traverse table with 6 tracks and a turntable at the end or just s standard staging yard.

Using the demand based car flow from my earlier post it shows 6-7 cars entering the layout on any given day. At the same time these cars will be spotted at various locations from he previous day s you can assume there will be 6-7 cars being loaded or unloaded on the layout. I also plan my waybills to have cars sitting to be loaded for more then one day in some cases so you could make the assumption that there would be 10 cars on the layout most of the time.

The above scenario results in 24 cars being required on the layout at any given time.

Staging 1 - Local freight 1- up to 7 cars
Staging 2 - Local freight 2 - up to 7 cars
On Layout - Up to 10 Cars

I want to run a variety of freight cars across the layout and not use the same 24 cars each session. When making up a train in staging i plan to use the demand based table and the process to be something similar to

- Look up Demand based Table for day of month (table needs to be extended to cover full 31 days.
- Table determines what cars are required by shippers and local agents.
- Make up train using a mixture of freight already in staging yard and from car draws below.
- Add Waybills to the car card pockets. and stage train ready for departure.
- There should already be 1 train in staging ready so this train will become the next operating sessions local freight.

Wanting a mixture of fleet to reduce seeing the same freight on the layout each time have double the figure of 24 cars to 48 and then rounded it out to 50 in total.

This figure of 50 doesn't include cars specifically for Murphy Lumber Co and also the logging fleet and it is likely this will bring the number up to approximately 70 cars in total.

 Next up its time to break down those 50 cars into different roads and home road cars that accurately represent 1929.

No comments:

Post a Comment