Thx bobby .

It is not something I have done much of the trick seems to be in selecting the right starting material.  I took 16 RAW images to start with ranging from 20secs exposure all the way through to 1/60th sec.  I found that by altering which ones I used I was able to get a result with detail in all areas. The final image is using 6 exposures.

I would have liked to have gotten a better composition, but the camera seems to have slipped in the tripod slightly on one showing the full arch so that sequence of shots is ruined.

And every one said, 'If we only live,
We too will go to sea in a Sieve,---
To the hills of the Chankly Bore!'
Far and few, far and few, Are the lands where the Jumblies live;
Their heads are green, and their hands are blue, And they went to sea in a Sieve.

Edward Lear
http://www.nonsenselit.org/Lear/ns/jumblies.html