Star Ferry, Kowloon, 1920s

Ths ship in the background is from the Dollar Steamship Line (see single funnel logo). 

Based on this website:

http://www.timetableimages.com/maritime/images/apl.htm

...there were 2 periods when it visited Hong Kong in the 1920s (which is generally accepted as when the photo above was taken)

1) January-May 1924

Ships were: 

President Harrison
President Hayes
President Adams
President Garfield
President Polk
President Monroe
President Van Buren

2) October 1925-September 1926

Ships were: 

President Monroe
President Van Buren
President Hayes
President Harrison
President Polk
President Adams
President Garfield

President Taft
President Wilson
President Lincoln
President Cleveland
President Pierce

Thus 1923 is early as a date. Is there anyone out there who could identify the ship? This might help narrow the date of the photo. 

@ "Is there anyone out there who could identify the ship? "

I will take a guess at this and state that this ship had some stage been the  S. S. President Pierce although it was soon renamed the S.S President Roosevelt  ( Update:  the source about the renaming of this vessel is now in doubt , having consulted the Lloyds Register of 1930. There are also other possibiblities for the ship's name....(see below)

The separation of the bridge from the cabin accommodation behind was quite unusual for the other R. Dollar vessels from what I can see. Also, the comparatively very short length where the sides of the hull increase in height at the prow ( gunwale ?) . ( I hope somebody with better sea legs than mine can correct my terminology).

Robert Dollar's company was taken over as American President Lines when it ran into financial difficulties.

The Wikipedia account of the ship's name changes is here  : https://en.wikipedia.org/wiki/SS_President_Roosevelt_(1921)   but not all shipping enthusiasts' sites seem to agree with the timeline and/or  name changes for S.S President Pierce . 

UPDATE

I have done some more digging and established that the ship in the photograph is almost  certainly one of the 535ft ( length) types designed and built in New York  (1920-1921) for the Pacific Mail Steamship Company.  Five ships were ordered and I have established from the Lloyds Register (of 1930)  these ships (of the same tonnage)  were named President Lincoln, President Taft and President Wilson , President Pierce and President Cleveland respectively. In 1925  the Pacific Mail Steamship Compnay was taken over by the ( Robert) Dollar Steamship Company .....the "Dollar Line". So from this information it would seem that the photograph is unlilkely to have been taken  before 1925. There is a picture of a typical Robert Dollar 535-Type steamship on a pamplet dated 1926 on this LINK here. 

Model-Steamship -535 ft. Type - Pacific Mail-Company, by Chinarail ( Enhanced scan from 'The Far Eastern Review' Sep.1920)

Plan of 535 ft. Passenger & Cargo Ship- Pacific Mail Service , by Chinarail ( Enhanced scan from 'The Far Eastern Review' Sep.1920)

Did a search on HKPL, the round-the-world service was inaugurated by the liner, 'President Lincoln'. The 'Lincoln' left San Francisco for the Orient on 12 May 1925. Upon arrival in Hong Kong, the 'President Lincoln' sailed to Manila on 12 June followed by a return trip and departure to San Francisco on 19 June. 

That's great sleuthing Chinarail and moddsey.

Here is another pic of one of the ships. It says the Dollar Line commenced from 1925 too

http://www.timetableimages.com/maritime/images/apl26i.htm

This is a painting of President Taft in 1927: it looks slightly different from the photo (esp. the bridge) in the ship, so we can rule that one out. 
 

https://www.mutualart.com/Artwork/President-Taft--Dollar-Line-Steamship/...

We can narrow the ship's ID to Lincoln, Wilson, Pierce or Cleveland

Here is a great photo of "President Wilson" in almost exactly the same orientation as the Kowloon Wharf photo.

https://www.shipsnostalgia.com/gallery/showphoto.php?photo=829058&nojs=1

It's a better match than President Taft but if you look closely at the bridge it's also not an exact match to the opening photo, so I'm inclined to think it's also not the Wilson. Which leaves 3 more ships to potentially match... Lincoln, Pierce or Cleveland.

Similar ships but are they identical?

Examining the two photos posted by Klaus with China Rail’s detailed plan I’m not sure that the PRESIDENT TAFT shown in the ppc view is the vessel berthed at the Kowloon Wharf.

In the post card photo of the PRESIDENT TAFT the line of windows on the bridge deck is continuous starting from directly below the front of the bridge. However, in the photo of the unidentified liner the line of ‘glass windows’ on the bridge deck below the boat deck start at the end of hold no 5 immediately aft of the separate bridge. (See China Rail plan)

The crow’s nest on the first goal post mast on the PRESIDENT TAFT appears to be positioned on the starboard post. This feature can be seen in other pictures http://www.navsource.org/archives/09/22/092204401.jpg

The PRESIDENT PIERCE also had this feature.

https://www.west-point.org/users/usma1955/20315/PHP.htm

On the unidentified liner the crow’s nest is clearly positioned in the centre of the mast.

I’ve gone through the list of Dollar Line liners listed for the periods previously posted and matched them up with available photo images on the internet.

Possiblties:

PRESIDENT CLEVELAND https://www.west-point.org/users/usma1955/20315/PH_6.htm

PRESIDENT  HARDING  https://humanscienceandculture.wordpress.com/2019/02/20/ships-and-scandal-the-s-s-president-harding/

PRESIDENT LINCOLN? no clear photographic image -  post card image captions  conflict

PRESIDENT WILSON https://vidamaritima.com/2012/10/cabo-de-hornos-y-cabo-de-buena-esperanza-2/ 

(President Wilson sold to Spanish owners)

Hope this helps

Regards

degahkg

Great find!  A very useful picture which keeps the PRESIDENT CLEVEVLAND in contention to be the ship in the Star Ferry photo. I do note a couple of minor differences. However, as there is a gap of several years between the pictures these differences may be alterations made over time or the quality / definition of the Flickr image.

As the four liners are sister ships built to a standard plan it may be difficult to pin point one ship.

Regards 

degahkg

Seems we are getting closer to answering the original question about  which ship and what date the photo was taken. Certainly we can eliminate dates earlier than 1925.

A February 1924 Shipping Notice in the Hongkong telegraph clearly indicates that a smaller class of Dollar ships were deployed on the Hong Kong Pacific routes to San Francisco . I haven't  enough time to go through  every newspaper ( it would take days.... weeks ? )  to check all arrivals and departures.

Hongkong Telegraph Newspaper- Shipping - Dollar Line -Feb.1924, by Chinarail

By 1925 we can see that the Dollar Line was using the larger class of 535 ft length "President" ships on their route to San Francisco . The sample extract from the Shipping Section of 17 Octopber 1925 Telegraph indicates that S.S. President Lincoln,  S.S President  Wilson and S.S. President Garfield (a smaller ship)  were on the route.

Telegraph-17-Oct.1925-R.Dollar-sailings.jpg, by Chinarail