[?]

As a general rule I use a 50:1 representation.  If there were 50 units in the real railroad then I will have one.  Exceptions are small types like GP15-2 or U23B which only had 20-25 units on the real railroad.  Since I can't have 1/2 a unit, I have one of those types to represent the class.  Also, on the East End, GE units were rare.  Regardless of how many the C&O owned, I will model only one of each type of GE locomotive.  Additionally, since it is a B&O line, a majority of locomotives should have B&O lettering.  I am shooting for 50% B&O, 30% C&O, and 20% WM units.  This break down actually over represents the WM units, that were always about 10% of the B&O or C&O total, but since the East End took on much of the WM traffic after 1975 in that area a 20% share of WM units is appropriate.

This roster plan is updated as of January 1, 2020.

STEP 1:
My first step was to find out how many of each class was owned by the Chessie System in the middle of the Chessie Era.  I found an Oct 1981 roster which worked perfectly.

I made the chart below to tell me how many of each I would need (using the 50:1 ratio as a rough guide).

There are a few adjustments made to tailor this roster more toward East End operations.  I decreased the amount of switchers, since these were not used anywhere on the East End except Cumberland.  So instead of 4, I will need only 2.  I have no BL2s, SD18s or SD20-2s, these classes all operated off the East End. 

SD7s and 9s are very small classes that could have been left off, except it was normal to have one as a helper at Martinsburg, WV on the East End and one in Cumberland where the routinely worked.  I therefore decided to model one of each class. 

I modeled only one of each type of GE locomotive, since they were rare on the East End. 

Additionally GP30s are overrepresented with 6 units.  This is my favorite class of locomotive so I did a few extra ones.  It's a little artistic license. 

The SD35 was a small class with under 50 units, but I am modeling 2.  One will be for the single unit needed to represent the class, the other will be TORCO 7800.  7800 is one of three ex-C&O SD35s owned by C&O subsidiary in Toledo.  These units worked the coal docks there and were equipped with remote control and had unique lights over the cab to show they were under remote control.  They are also the only three units that wore the Chessie scheme without "B&O", "C&O" or "WM" sublettering.  They had "TORCO" sublettering.

There are also several classes (GP15T, SD20-2, slugs and SD50) that were added after 1981.  Since I want to model some of these, I added them to the chart.  I also added F-units, even though they were all retired by 1981.  I use a little creative license to extend the service life of two WM F-units a few years.  The other F-unit is C&O 8501, it was a modified F7B used to haul prime movers around the system.  It looks like an engine but can't move on its own anymore, however was still kept on the roster.  It lasted on the roster much longer than the WM F-units.

This chart is color coded as follows:
Green:  In the "Already Purchased" column this color means that all of the necessary kits have been purchased.  In the "Already Completed" column this color means that the class is completely modeled or none will be modeled.  If the "Already Completed" column is green, than the whole line is green, showing that no more work will be done on that class.
Orange: Work is underway on this class.  In the "Already Purchased" column, some but not all of the necessary kits have been purchased.  In the "Already Completed" column, this color means at least one example is done or one is currently on the work bench.
Red:  In the "Already Purchased" column, no units in this class have yet been purchased.  In the "Already Completed" column, this color means that no work has been done on any units in this class.

Class	Prototype Total	Need (50:1 ratio)	Already Purchased	Already Completed	Notes
GP7	162	3	3	3	DONE
GP9	500	10	4	2	Many more Athearn, P2K and Front Range to purchase
GP15T	25 (add post '81)	1	1	1	DONE
GP18	1	1	0	0	P2K makes a decorated model of B&O 6599
GP30	111	6	6	6	DONE (when the last Chessie B&O in work is done)
GP35	85	2	2	0	Two Kato undecs purchased, but not started.
GP38	130	3	2	1	Need to buy another Atlas one.  The All-American Locomotive #3802 will be one.
GP39	20	1	0	0	No kit available
GP40	215	4	4	2	One Athearn GP40-2 backdated to WM #3798 to do.
GP40-2	346	7	7	3	2 completed units have sound.  2 purchased units also have sound.
SD7	5	1	1	0	One P2K purchased.  Need to get around to detailing it.
SD9	10	1	1	0	One P2K purchased.  Need to get around to detailing it.
SD18	19	0	0	0	NONE
SD20-2	5 (made after '81)	0	0	0	NONE
SD35	32	2	2	1/1	B&O unit done, TORCO unit to go
SD40	83	2	0	0	Need to purchase 2 of the new Athearn kits or the older Kato ones.
SD40-2	20	2	2	1/2	1 dummy done, 1 dummy to go
SD50	0 (add after '81)	2	0	0	Athearn kits on market, but a low priority since they are post 1982 purchases.
U23B	30	1	1	1	DONE
U25B	0 (ret before '81)	1	0	0	Will buy a Stewart/Bowser model when I find one for a reasonable price.
U30B	35	1	1	0	Have Athearn dummy.  Need to get around to detailing it.
U30C	13	1	1	1	DONE
B30-7	64	1	1	0	Purchased the Atlas kit, but haven't gotten to it yet.
F-Units	0 (ret before '81)	3	1	0	Many good offerings on the market.  Looking at Stewart ones.
Switchers	191	2	1	0	Have one Atlas Chessie B&O S4.  Second will be Broadway Limited B&O 5065.
Slugs	12 (add after '81)	1	0	0	No kit available.  Will have to scratchbuild one.

STEP 2:
Next take the amount you need of each class and apply it to the chart below.  The chart below lets you know what paint jobs each of the classes came in.  Try and keep to the ratio you set for yourself.  Mine is 50% B&O, 30% C&O and 20% WM.  Also, I try and have about 50% of the total units in Chessie paint and the other 50% in predecessor paint jobs.  That will give a nice middle of the Chessie Era feel to the roster.

Key:
Green blocks are locomotives and classes that are completely done
Yellow blocks are locomotives currently in work.  In the class column, yellow refers to some of, but not all of the class has been completed
Orange blocks are locomotive kits I own but have not yet begun construction on.  Orange in the class column means that kits for this class have been purchased, but none are yet completed.
Red blocks represent locomotives that I do not own yet.  Red in the class column means that no kits have even been purchased yet.
Black blocks represent that no unit of that type ever appeared in that paint scheme

Number Key:
1  :  1 of this type of locomotive in this paint scheme will be made for my roster.  This notation signifies that all of the locomotives in that block are in the same stage of completeness.
1/2/1: 4 total locomotives of this class will be made.  1 is completely done, 2 more kits have been purchased, 1 has not been bought yet.  This notation is used when multiple units are going to be built of that locomotive in that paint job, and the kits are in different stages of completeness.

Notes:
LO PRI: This class is a low priority for me now.  Most likely due to the fact that a suitable kit is not currrently available.
HI PRI:  This class is a high priority for me now.  Most likely Atlas, Athearn or Life-Like P2K make a great matching kit for this class and I am working on that type now.
DONE:  No more of this class will be built.  The units I have already built are a proper representation of the class.
NONE:  None of this class will be made.  In the SD18 case, they lived in KY yards primarily, and I have never seen one anywhere near the East End.  The WM BL2 locomotives are not listed here.  There were only two, both lived in Hagerstown, MD all of their Chessie lives.  I will not be modeling any of this class of locomotive since they never appeared on the East End