Diana Harris, author of the "Ultimate Force" companion book, graciously took the time recently to answer questions from Ross Kemp Fansite visitors about the book and the series. Her book was first published in October 2002 by BT Batsford, and is available through Amazon UK and other outlets.

Q: How did you come to write this book?

A: I was commissioned to write the press pack for the series which is sent out to journalists, when I soon realised that viewers might also be interested in a book which revealed how it was made and explores the Top Secret world of the SAS. I suggested the idea to the executive producer, Brian True-May. He agreed and I approached BT Batsford, part of Chrysalis Books. I then had about six weeks to get it done!

Q: How did you prepare for writing it (research, etc.)?

A: I spent a long time reading up about the SAS to get background, I read Chris Ryan's books, looked up information about weapons on the Internet and basically tried to soak up as much about the SAS as I could. My research for the content of the book was carried out by interviewing most of the cast and production crew, including Chris Ryan himself. I also had long conversations with the series creator Rob Heyland about how he conceived the characters.

Q: Can you tell us a bit about the locations you were on, and what were the filming conditions like there?

A: Although series 1 is set in three very different locations, England, Northern Ireland and Bosnia, most of the filming was done within a 20 mile radius of London due to tight budgets. I was very impressed at how places a few miles apart were made to look so different. One of the days was spent in a park near Pinewood Studios which had old farm buildings which were transformed into a Bosnian hideout. For the SAS headquarters near Hereford, producers used the old airbase at Upper Heyford once used by the US army. For the episode about SAS selection, 'recruits' had to cross a river. In reality this meant spending hours in a freezing cold weir. Luckily the producers had provided a hot tub so that the actors could get in and out to warm themselves up between shots.

Q: How long would a typical day's filming be?

A: 12 hours on camera, typically 8am to 8pm but this means getting there perhaps 2 hours beforehand to do make-up, get the actors into costume and set up the first scene ready to start the cameras rolling. Obviously there were plenty of night shoots too.

Q: To what extent were the cast allowed to do their own stunts?

A: Insurance policies prevent the cast from doing anything too dangerous as it is not worth risking injury. However the actors learnt to fire their own weapons and reload them as well as choreographed fight sequences. For the episode where Jamie Dow is kidnapped and tortured, actor Jamie Draven was knocked about a bit by his 'tormentors' and came away with some real cuts and bruises.

Q: Were there any things which went wrong during filming ("bloopers") which you could share with us?

A: Ross Kemp was burnt on his arm when a special effect went wrong but luckily it was fairly minor. In the new series, Danny Sapani who plays Ricky Mann accidentally stuck a knife right through his finger. Luckily it was really a flesh wound but the blood viewers see on screen is real!

Q: From an author's point of view, how did the characters of Henno and Jamie Dow meet your expectations?

A: SAS soldiers come from all walks of life and this is shown in Henno and Jamie. Henno is a top soldier and a natural leader and Jamie is a young man who found in the SAS a way to escape his difficult background and excel at something. They are well portrayed by Ross Kemp and Jamie Draven. Interestingly, most of the character names, including Henno Garvie, come from real people in Rob Heyland's cricket team, while Jamie Dow is the name of his godson.

Q: Besides Chris Ryan, were any other former or current military personnel consulted for the series?

A: The producers spent time with a number of former and serving SAS personnel but they cannot named. The new series features another former SAS trooper, Derek Horne, who is now an actor and plays trooper Sean Smith.

Q: Noting the controversy surrounding former SAS members sharing their stories, do you know if there was any resistance to the series being made (from any quarter, official or otherwise)?

A: The Ministry of Defence has a policy of no comment and no co-operation on talking about the SAS so they did not reply to approaches made by the production team. However, real SAS troopers have told Rob Heyland and others unofficially that the series is an accurate reflection of the real regiment. Many of the incidents are based on real life and the SAS apparently particularly like the way their gallows humour is portrayed.

Q: Of the filming that you saw, which scenes seemed to be the most fun for the cast to do?

A: I think they enjoyed the action sequences, using 'boys toys', wearing the SAS 'blacks' etc. They also enjoyed any meaty dialogue scenes with deeper characterisation. Ross Kemp even told me he enjoyed a scene wading through a 'sewer' full of specially-provided rats!

Q: Can you tell us a bit about the safety precautions that were taken during filming?

A: Every location has to have a health and safety assessment and any appropriate action taken. For example, if any fuel is found at a scene it has to be cleaned away using special procedures and major explosions require a fire crew standing by. Obviously a particular hazard is weapons as even blank ammunition can cause an injury. Home Office regulations require licenced armourers to be on set at all times when weapons are present. The cast all underwent weapons training and every gun was painstakingly counted in and out and checked between scenes. A unit nurse was also on set at all times but luckily he spent more time handing out flu medicines to the crew than dealing with emergencies from filming.

Q: What was the most dangerous stunt or scene to film?

A: The most dangerous stunt was when Laurence Fox (son of actor James Fox) had to swim in the weir in winter. The river was swollen and freezing and the sequences took a whole day to film. Even though Laurence had a hot jacuzzi, cups of tea and wore a dry suit under his uniform (unlike real soldiers going for SAS selection who have to strip off), he still felt he earned his money that day! The stunt co-ordinator was Colin Skeaping.

Q: For a firefight scene, what was the average setup time compared to the actual filming time?

A: Normally you can achieve 5 minutes of cut film for a day's work, but for this type of action sequence you would only achive 2.5 minutes as it entails twice the amount of set up time in accordance with health and safety regulations, and to allow time to choreograph the real actors alongside the stuntmen. There is a wide margin allowed on these types of shooting days to ensure that the budget for pyrotechnics, ammunition and fire fighting is wisely and safely spent.

Q: How did the cast pass the time between scenes?

A: On one occasion Alex Reid who plays Caroline Walshe brought the lads water pistols. It was near the end of filming and she thought they would miss their guns. So they passed the time with a huge water pistol fight. Jamie Bamber also trained for the London Marathon while filming series one although I don't think he went on any long runs between scenes!

Q: Are you or will you be working on anything in relation to series 2?

A: I have written the press pack for Ultimate Force II which is currently being transmitted on ITV1 on Wednesday evenings. This involved interviews with the cast and crew once again. I have also written an article on Ross Kemp for the Sun TV Mag.

Q: Is there a possibility of a third series? If so, at what stage of development is it at now?

A: I understand that Bentley Productions has begun developing scripts for a third series and that there is a possibility of filming some sections overseas. It still has to be commissioned by the ITV Network.

Q: Tell us about other books you've done.

A: My other book so far is on The Vice, another ITV1 series, which follows a vice squad working in the areas of prostitution and pornography. This was a novelisation of several scripts so did not require any lengthy research in red light districts!