Achievable?

Hi all,
I am travelling in mid March from Shin-Osaka to Hakata and want to see Himeji Castle and Hiroshima on the way down.We will be leaving our luggage at Himeji and Hiroshima Station lockers. If we leave Shin-Osaka at 8.14 we arrive at Himeji at 8.56, deposit luggage in lockers and walk to castle 9.20.We would spend about 2.25 hours there before heading to Hiroshima.
Leave Himeji at 12.07 arriving at Hiroshima at 13.34 and deposit cases in storage.Knowing that the Miyajama Island is undergoing reno's we would jump on one of the 3 free (JR Pass holders)loop buses for sightseeing.This would give us approximately 3 hours. We would then depart Hiroshima at 16.48 for Hakata arriving at 17.58.
Do you think this is achievable?
Thanks for any replys in advance,
Cheers

Do you think this is achievable?

Yes.

1. You may better take earlier Hikari or Sakura or Kodama to Himeji. Finding coin locker might be difficult for the first timers, though there are many coin lockers around Himeji station.

2. Take left window seat so that you can see Setonaikai inland sea and Akashi bridge.

3. Hiroshima to Hakata is not so interesting so you might better stay in Hiroshima longer to have dinner and then late Shinkansen to Hakata.

I agree with @frog1954 that you are arriving too early in Fukuoka. Just plan to be there with one of the last trains. (In that case, best reserve a seat)

Himeiji castle can have some long queues so you might need longer than expected but you could still have time in Hiroshima before arriving in the evening in Fukuoka.

Enjoy your trip to Japan!

Unless you want to get to Hakata in time for (a yatai-crawling?) dinner there.

You can take a bus instead of walking to Himeji Castle, to save a little time.

Thanks all.
It may be a bit tight but should make it to Hakata.
I will be trying to get the Shinkasen from Hakata to Kumamoto the next day and travel on the SL Hitoyoshi steam train if I can eventually get the timetable for March 2020.
Cheers

You can send your luggage to the hotel in Hakata by gtakuhaibinh or gtakkyubinh on the previous day so that you will have no need to walk around to find a vacant coin locker at Himeji and at Hiroshima station.