The combination of Tony Scott as director and Denzel Washington as lead actor is nothing new. They teamed up for four films prior to "Unstoppable", which have been generally very good films. However, for "Unstoppable", they have combined to bring us something new; this is possibly the first Denzel Washington film that I ever recall not enjoying.

In "Unstoppable", Will Colson is paired up with Frank Barnes to run a train delivering some carriages. There is immediately some friction, as some of the older workers like Barnes have been forced to take early retirement and are being replaced by people like Colson, who are cheaper to hire. Distracted by this and by a domestic situation involving his wife, Colson picks up too many carriages on the train.

This is not the only mishap to occur on the rails that day, however. In trying to move a train from one track to another, a guy called Dewey jumps off his train to change the points and trips before he can get back on. This allows the train to run down the track on its own at very high speeds into the path of oncoming train traffic. This oncoming traffic includes a train full of school children, Barnes and Colson's train and the track it's on could ultimately take the runaway train, which is carrying harmful chemicals, into a densely populated area.

The basic storyline has the potential to be an exciting one, with a train that could potentially cause a huge disaster. The film switches between the runaway train itself, the various attempts to get it stopped and the people in the office controlling everything that's going on. Add to this with the sub-plots of the building relationship between Barnes and Colson and Colson's own personal situation and the elements are here for the makeup of a very decent film indeed.

Somehow, though, it never quite makes it. Perhaps it's coming so soon after the remake of "The Taking of Pelham 123", which was also a combination between Tony Scott and Denzel Washington and a film I rather enjoyed, but I just didn't feel the tension was here. This lack of tension doesn't help, as it then strands the film in the mire of the action thriller genre when you know from the off that the outcome is barely in doubt. There simply isn't enough here, despite the character building, to elevate the film anywhere above the simply mundane.

It's hard to pin down exactly why the film didn't work for me. Individually, the elements that make up the film are generally pretty well done. The direction and script work well to try and keep the pace high, with frequent cuts between one scene and another; the train, Connie in the yard, the guys on various trains, the news feeds. Given that much of the film focuses on two guys sat in a train cab, or others sat in an office, this was important as there was plenty of potential for this to have been a very slow moving film. There are plenty of scenes set up to try and raise the tension, usually involving some kind of disaster caused by the runaway train. Unfortunately, all of these latter scenes felt to me as if they were staged deliberately to try and raise the tension, particularly one scene with an accident and the horses on a railway crossing, and without the suspension of disbelief that was required, especially as the film is supposedly based on a true story, the tension simply wasn't there.

The acting performances were pretty good as well, with all the main cast putting in a decent, if unspectacular effort. Denzel Washington as Frank Barnes and Chris Pine as Will Colson work well together. Their starting point of mutual suspicion, gently moving towards a mutual appreciation of each other and an easy comradeship, if not exactly friendship, is well done and in the hands of these two, reasonably believable, although they do perhaps move onto personal information a little more readily than most would. I particularly liked Rosario Dawson's performance as Gail, as she has played a number of very strong women and this is another of those, although in a totally different context to her performance in "Sin City", but her strength and determination came through nicely. The one area in which "Unstoppable" won out over "Pelham 123" was in Kevin Dunn's portrayal of Oscar Galvin, in which he melted down under the pressure far more effectively than James Gandolfini's mayor did in the latter.

The script wasn't too bad and this helped with the character building. Although the relationship between Barnes and Colson seemed to me to grow a little too quickly, they had some good lines between them. Some of the early lines allowed for some sniping between characters and later softened, to show the relationship become warmer between them and this worked rather well, I thought. In a well worked contrast, the relationship between Connie and Galvin never achieved this and their parts of the script were far more businesslike and abrupt. In what feels like a completely unrealistic situation for much of the film, the script at least allows the relationships between the people concerned to come across as reasonably realistic.

The special effects seemed quite effective, to my untrained eye. Admittedly, crashing and exploding a train isn't going to be one of the easiest things to portray on screen, but they achieve it and it seemed to look reasonably good to me. One particular effect with the train towards the end was entirely unbelievable, but even coming at it from that perspective, it looked pretty good on the screen. I may not have been able to shake the feeling that it required more suspension of disbelief than I was prepared to give it, but I couldn't see the joins at the edges of what must have been computer generated and what wasn't. The stunts which, again, usually involved people jumping onto and off of trains and accidents involving the train also looked fairly well done and I didn't notice any glaring errors during those scenes either.

The soundtrack wasn't particularly memorable, although in many cases, the sound of a train at high speed was allowed to speak for itself, which was perfect. Personally, I prefer a soundtrack that doesn't overpower the visuals enough to be memorable, so that's another area in which I felt the film was a success. Indeed, about the only part I can remember is what was played over the end credits, when the soundtrack is supposed to have its main moment. I can't claim to have been overly keen on the music played there as it's not a favoured genre of mine, but it did seem to be in keeping with some of the characters in the film.

All of the elements that went to making up the film seemed to be in place, but somehow the whole was less than the sum of its parts. It's a very well put together film and the basic idea should be gripping and thrilling. But for some reason I can't explain, it didn't have that effect on me. Perhaps it was just that the whole idea, despite supposedly being based on true events, seemed so farfetched that I was never entirely able to relax and enjoy the film. Maybe it was that the film came a little too soon after "The Taking of Pelham 123" and seemed to me to be inferior to the earlier film that unsettled me. For whatever reason, this is a film that wouldn't be too bad if you see it on a free to air basis, but I can't recommend spending money on it, even though it can be found for as little as 99 pence on eBay or £2.85 on the Amazon Marketplace, plus postage. It's a well crafted film, it just failed to excite me in any important way.