Train Transfer times

I am worried about train transfer times with luggage. We have 9 minutes for Shinkansen Kodama at Shin-Osaka to Shinkansen Sakura (track 24 to track 20.), going to Okayama.
Then, in Okayama, we have 8 minutes to go from Track 21 to Track 8 for JR Marine Liner 23.
Will this work? We have reserved seats on each train.
We had hoped to ship luggage ahead but next day is not possible (which we need) due to high travel now -- April.

It depends on how fast you are and how good you are at orientation. It would be no problem, at all, for people without luggage and familiarity with the stations to make these transfers. But people who are slow with luggage or prone to taking the wrong way, may miss the connection.

The fact that you already know your track numbers suggests to me that you won't have a problem with the transfers, assuming that you are not slowed down too much by your luggage.

Both stations are straight-forward with all the platforms arranged parallel to each other. Especially the transfer at Shin-Osaka will pose no problem. Just look out for your car number. Okayama is just slightly more challenging as you have to pass through the ticket gates, but eight minutes is a surprising large amount of time.

Going from Shinkansen to Shinkansen tracks means going down the main level on one escalator, walking over to a second escalator, and going back up. You should be able to manage that in 8 minutes.

Going from Shinkansen to a regular train is more difficult. You normally have to go out of the Shinkansen area gate, and enter the regular train area gate before you can get to the regular train concourse. Okayama's Shinkansen gate is on the end of regular train concourse, so it has a better layout for making transfers.

I have made the transfer from the Shinkansen to a limited express in 6 minutes at Okayama. I had two pieces of rolling luggage with my daybags strapped to the handles, but I did make it.

What freaked me out was actually getting on the car and finding my seat was taken. I thought I had pushed myself hard, only to get on the wrong train.

After showing my ticket to the conductor to make sure I was on the correct train, the conductor severely chewed out the passenger, and almost threw him off the train. I had a green JR Pass at the time, and the passenger had a regular seat and not a first class seat.

Okayama has one of the better layouts for switching from a Shinkansen to a regular train. It's down the escalator, out the gate, and you are on the concourse for the regular trains. If you cannot manage the escalator with your luggage, you will have to find the elevator, which is also nearby.

Traveling first class on a Marine Liner was my first experience in the front seat of a train where I could look out the front window. I could see past the train engineer who is running the train. If you are in the first row, you are next to the clear wall that separates the five foot wide engineers compartment from the passenger area.

I hope this helps.

The platform numbers are clearly labelled once you head down the escalator or stairs. The only problem here would be how much luggage you have, and how fast you can move them.

8 minutes is a lot of time for shinkansen to shinkansen transfer. Hell, during my last trip I had a trasnfer and it happened to be on the same platform!

We have 9 minutes for Shinkansen Kodama at Shin-Osaka to Shinkansen Sakura (track 24 to track 20.), going to Okayama.

If you cannot choose staircases due to your luggage, in Shin-Osaka Station you need to take 3 escalators or elevators, so you may have to wait when an escalator or an elevator is crowded, maybe all the 3 times.

In Shin-Osaka Station there is no direct staircase / escalator / elevator between the Shinkansen concourse and the Track 20 platform. (There are 2 separate pathways between them each via a middle floor.) Arriving to Shin-Osaka at Track 24, you can go down directly to the Shinkansen concourse. From the concourse, you can get to the Track 20 platform taking 2 escalators upward, or taking the first elevator (for Tracks 20 -22) upward and the second elevator (for Track 20) upward.

- Map of Shin-Osaka Station
http://english.jr-central.co.jp/info/station/_img/shin_osaka_L.jpg

Then, in Okayama, we have 8 minutes to go from Track 21 to Track 8

Track 21 and Track 8 of Okayama Station are around its different ends, east and west. So, if the travelers include a slow walker, it may be better to expect a little more time for the transfer.

In Okayama Station, you can pass through a Shinkansen Transfer Gate between the Shinkansen and the non-Shinkansen zones; in other words, you will not need to pass through an exit gate or an entrance gate. Each platform of Okayama Station is equipped with at least two escalators and one elevator.

- Map of Okayama Station (with signs in Japanese)
http://www.jr-odekake.net/eki/premises.php?id=0650608

Thank you all for this great information. It will be most helpful to have an understanding of what we will need to do.
Linda