An article which appeared in the Glasgow Herald on the 24th August 1903 reported on an inspection of the Clyde Defences by the CinC, Lord Roberts.

Descriptions of visits to Ardhallow, Portkill, Fort Matilda with mention of construction of Cloch Coastal Battery also makes mention of a fort at Scalpsie Bay.

Does anyone know if it was ever built and if so what happened to it?

That sounds like a lazy journalist writing an article from looking at a map and making things up to embellish it and enlarge their cheque...

There is indeed a fort at Scalspie, on the western side of the bay.

But it's an ancient vitrified fort!!!

There's only stone and rock to be found there.

As I recall, there's at least three of these vitrified Stone Age Forts there.

I don't recall a name on that one (I'd have to dig out some references), but there is Dunstrone Fort to the south, and then Dunagoil Fort still further on.

I don't remember reading of any modern are forts, but I could of course be wrong, or have missed it over the years.

This has all been fairly extensively documented over the years, by the historical society on Bute, and their work dates back some time. There have also been some very detailed modern evaluations to, in more recent years.

Modern era items include a decoy village near Rhubodach ferry terminal on the north west (may be remains, but never found so far), and a pillbox in the area of the modern car park at Ettrick Bay, near the tearoom. But this cannot be found either, having collapsed leaving only some concrete as evidence.

Ah!...

Here's the link needed - hours and hours of reading and detail here (maybe even a fort I missed)...

Bute - Background Information

Bute Heritage, History, Archaeology &Genealogy

I'm afraid you might find some of the links no longer work - when the original maintainer passed away, his material was eventually lost as no-one there thought to take over and maintain it all properly. Can't say this came as a surprise as we had often spoke of how short-sighted the folk he did this for were. They didn't even accept volunteered help for some sort of fear of liability they had talked themselves into. As a result, many articles and pictures have 'evaporated'.

Ardnahoe fort - no wonder I never remember that one.

Possibly obvious, but they can all be found in Canmore.

On old-maps there are two fields that suddenly become one and an interesting shape quite suitable for a battery.   No details of course but I didn't expect to find any.  

Slipping my slightly more serious hat on for a moment...

It could be that there is indeed some sort of story and perhaps even an official memo or two rolling around somewhere in relation to this, and the story has genuine foundations.

But, I suspect the foundations could be the downfall of the story too.

It's possible that some planner had a look at the maps, saw the site looking out into the Atlantic, and decided he had found a handy spot to drop some defensive guns and a battery onto.

The problem would lie in the make-up of the ground, and the underground parts we see supporting such batteries.

Most of the ground is solid rock.

What looks like grassland generally turns out to be a thin coating of earth over rock - this makes it difficult to establish any sort of facility that requires underground rooms, and even surface installations that require a level base on which to be establish still require that to be established, either by hard labour, or explosives.

If there was indeed a reference to this place for a fort, or a perhaps a battery, then I am pretty sure that the visit mentioned in the opening post would have led to this particular site being rejected as requiring too much effort.

However, if there is a report floating around, either to the contrary or confirming this thought, it would be a pretty good find

There are a lot of mentions in newspapers of the Volunteers having annual camps at Scalpsie Bay but can't see anything about a battery being planned there.