In my post about the Crescent Star being a reality posters have started to consider inventory and equipment assignment for the new route. It is not the first instance this has been done. For most if not all new LD routes, sleeper cars are considered a requirement. Some people also have said a diner car is also a requirement but it is clear that Amtrak is low in inventory of sleepers and diner cars and the Silver Star has no diner car and several others have "diner lite" (has the full diner returned to the LSL?).
However, I don't feel that a diner car or even a sleeper should be a requirement for starting a new LD route (preferable for sure but not a requirement). I'm sure many of you regularly or always use sleepers for LD service. I remember one poster lamenting about sleepers on the Cardnal being ridiculously expensive compared to other eastern LD routes (LSL/CL) and he was right. On the other hand I found coaches for the same day to be cheaper than the others. But I have never rode a sleeper on any LD train and I've gone cross country three times.
But in many LD trains, a huge majority of LD passengers travel coach class. According to NARP stats, about 10.3% of LSL passengers, 12.5% of SM passengers, and 17.% of SWC passengers ride in sleepers. The average LD passengers doesn't travel anywhere near the full route (neither does the average LD sleeper passenger). But even for passengers traveling the full distance (or close to) for several trains a majority of them still ride coach. Looking at the bars between the coach and sleeper, it looks like about 2/3 of passengers on the LSL travelling 800-899 and 900-999 miles still ride coach that length. A similar phenomenon exists for the SM traveling 1100-1199 and 1300-1399 miles. For the SWC, the breakdown for >2000 miles is roughly 50-50 between coach and sleepers. For the CZ, more >2000 mile passengers ride sleeper but more passengers between 1000-1099 (probably CHI-DEN, around the same distance as CHI-NYP or NYP-ORL) passengers ride coach.
This being said, I strongly believe a sleeper-less LD train can work (although not for a longer train like the SWC or CZ). The Night Owl has no sleepers at all. In the past, the Three Rivers did not use sleepers for the first year or two, the case when I rode the train in 1997 (http://www.timetable...0511n&item=0026). If the only reason the Capitol Limited/Pennsylvanian through cars aren't in service now is a lack of sleepers, I think they should just start the service now without the sleeper car and add the sleepers if/when they are available. In this case, passengers east of Pittsburgh can ride coach through PGH and get a sleeper at PGH. Maybe no one here would ride it and would probably ride another seven hours CHI-NYP or CHI-PHL just to use a sleeper but I'm pretty sure enough passengers will ride coach between those cities (as well as others) as a significant number of LSL/SM passengers ride coach between NY-Chicago and NY-Florida now. And this is not even talking about diner cars which for any new car, especially for Viewliner cars would be a given. But just like the Silver Star now, the Three Rivers's sleeper fares 30 lower than other LD trains because of a lack of a diner car (https://csanders429.wordpress.com/trains-and-routes/three-rivers/). I think it does work for a route where there is another option (LSL-TR and SM-SS) and if the alternative between a sleeper-less ride is a four hour layover in PGH at their Am-shack at night, I'd take the sleeper-less ride any day of the week.
So IMO get the service first and add the sleeper later (and the diner later on). The lack of sleepers is not an excuse for expanding LD trains/options (unless coach cars and other required equipment is in as short supply as sleeper/diner cars). If you don't want to ride 1000 miles in coach, don't. But don't deny me (and others) the right to do so.