Malcolm Laughlin <mlaughlinnyc@...>
There have been a few comments on this topic in regard to waybills and how do we get randomness so that there is the possibility, as Tim O mentioned for example, of having four SFRD reefers on the same switch run to Frederticksburg Cold Storage. At our club there are two techniques that use in making up four part waybills that help with this.
1. Our layout has enough complexity that it can take from twoto seven days to go through the foutr parts of the waybill. I try to combine trips in a manner that gives different cycle times.
2. I will make 1/4 to 1/3 excess waybills for a car category. When a car gets back to the fiddle yard on cycle four, the waybill is pulled and a diferent waybill is put in the car pocket. Here's an example using meat reefers.
We have about 30 meat cars with about ten different meat companies. The waybill on part 1 has the shipper (meat packer) highlighted and the car pocket clearly identifies the packer. For each packer, I've taken actual origin points from the OpSIG industry database. When a meat car returns to the fiddle yard on part four, we draw another waybill for that packer.
For produce, we have a set of waybills for PFE and SFRD reefers. Each has two round trips from actual origins on UP, SP or SFRD as appropriate. I will always combine a round trip for an move to a local industry, which can take two to four days, with an overhead move to get the cycle length (pseudo)randomness .
These techniques give us a nice variety of moves and what you will see at any given operating session is quite iunpredictable.
I'm copying this to the OpSIG, something we might want to discuss.
Malcolm Laughlin, Editor 617-489-4383
New England Rail Shipper Directories
19 Holden Road, Belmont, MA 02478