Scott, I'll do my best. The best way to see this is to refer to the D Stairway photos on posts 5, 6 and 7 here -
https://www.theqe2story.com/forum/index.php/topic,2296.0.html. Also use the photos in post #13 here -
https://www.theqe2story.com/forum/index.php/topic,63.0.html. It will also be helpful if you have this link open in an adjacent window -
http://rmsqueenelizabeth2.com/map/decks4_5/4deck.html.
The D Stairway stairs from 3 to 4 Deck continue spiraling on the port and starboard sides as they do from 1 Deck down to 3 Deck except that there are no lifts, colored ballustrades and no open center (see post #5, 4th photo). Once the stairs land on 4 Deck there are three ways to proceed down to 5 Deck but, again, no lifts. Two staircases are very narrow, are mirror images of each other and are right at the bottom of the port and starboard landings at 4 deck (see post #13, 3rd photo). The 3rd way is just forward of the landing and is a "normal" width.
First, the two narrow, mirror image staircases. At the bottom step at the 4 Deck landing you are facing inboard and the opposite stair "tower" coming down from 3 Deck (post #6, 1st photo). Turning to face aft (turning left coming down the starboard side stairs and right on the port side) you will proceed aft down a thin, approximately 3 1/2 ft wide stairway to an intermediate landing on "4 1/2 Deck" (post #6, 2nd photo) where the stairs turn 90 degrees to face outboard. Continuing down the last half deck, these stairs land at the port and starboard main passageways on 5 deck (post #6, 4th photo).
The third route is a bit more difficult to explain. Landing again at 4 Deck you are facing inboard (post #6). For an excellent perspective, click on the D Stairway on 4 Deck on the virtual tour here -
http://maritime.elettra.co.uk/qe2/. When the interactive photo opens you will be facing forward with the above two decribed small stairways to your back and the two stairways decending from 3 Deck to your left and right. Turning 90 degrees at the landing of the 3-4 Deck stairway or proceeding forward in the virtual tour photo, walk forward a few feet and you will find a "normal" width stairway on your left proceeding down and outboard to port. That stairway also has an intermediate landing at 4 1/2 deck, turns 90 degrees to the left to face aft and lands in an athwartship's (side to side) passageway connecting the port and starboard 5 Deck main passageways just forward of the two small 5 Deck, D Stairway landings (post #7, 1st and 3rd photo - same photo, slightly different angles).
D Stairway in review: normal stairs with lifts, ballustrades and open centers from 1 to 3 deck, spiraling staircases with essentially the same width from 3 to 4 Deck with no lifts, open center or ballustrades, then three separate staircases from 4 to 5 Deck. The two mirror image staircases leading down and aft are right at the 4 Deck landing, about 3 1/2 feet wide, turn outboard at an intermediate landing half way down and wind up in the port and starboard main passageways on 5 Deck. The third staircase is a yard or two forward of the 4 Deck landing, proceeding down and outboard to port, turns aft (90 degrees to the left) half way down and lands in a cross passageway.
Hopefully that clears things up for you. Let me know if you have any questions.