"That week I wasn't even on the ground," says Urban. "[I had] butterflies in my stomach all week long, realising that I'd been given the opportunity to be part of something that I'd desperately wanted to be part of and, to a certain extent, I still feel like that," he says, without one crack of a smile.
Even out of the armour, Urban is a fierce presence.
He says working on LOTR was just as intoxicating as people might expect, given the project's big names, big budget and even bigger scope.
"Sometimes I still can't believe I'm a part of the whole thing. It's really a special part of my life. I feel very privileged and proud to be a part of it."
Urban's mother worked for a production company and he had an early start in show business with a small part in a television programme. His first line was, "They've got no proper clothes on," which he exclaimed while peeping through a window when he was 8 years old. Once he finished secondary school he got back in front of a camera.
He did the obligatory stint on Shortland Street, spent a year at Victoria University, and had a part in the short-lived children's drama Riding High.
Recurring roles on Hercules: The Legendary Journeys and Xena: Warrior Princess and some meatier film roles followed, including the part of a cameraman in the drama Via Satellite, which earned him a best supporting actor nomination.
"I never know what project I'd like to be involved with until the script lands at my door," he says.
"If I read a piece of material that pulls some strings, if I start to feel for the character or I start to make decisions on these characters, or I find myself getting lost in it, then that's a pretty good sign."
In LOTR, Eomer defies his uncle, King Theoden, by leading Rohirrim soldiers into the border region invaded by the evil Orcs and Uruk-hai. A scowly, deep-voiced, armour-suited Urban features in the trailer for The Lord of the Rings: The Two Towers.
"I actually had to maintain a consistent gym routine to keep my back strengthened because I don't usually walk around with 15kg of clothes on, but it was cool," says Urban. "Once you put that armour on, you can't help but feel like a fierce Rohan warrior. It really does embody the physical presence of the character."
It wasn't just the armour that was a challenge. Inclement weather, hunger and fatigue all took a toll on the cast but Urban swats away the notion that some days were less than pleasant.
"If you were to ask yourself whether you would rather be doing anything else or being somewhere else, the answer is a definitive no," he growls. "It's what you love doing and you wouldn't trade it for a million bucks."
Swordplay and riding horses at full tilt were other skills he picked up on set, and he really enjoyed working with Jackson, actors Viggo Mortensen and Ian McKellen, costume designer Ngila Dickson and special-effects whiz Richard Taylor.
After LOTR, we will see Urban in Ghost Ship, a horror starring Juliana Margulies and Gabriel Byrne. Urban plays a member of a salvage crew which boards an abandoned Italian luxury liner 40 years after tragedy struck. The ghosts of dead passengers warn them to leave but, no surprises here, they choose to stay on board, hoping to find valuables.
Urban is tight-lipped about what comes next. One thing's for sure, his recognition factor is about to skyrocket.
"I'm not one to speculate about the future, especially not when it comes to acting. There are no guarantees, but I do know one thing. I know the exposure I'm going to get from this film will be far greater than any other project I've done to date.
"I haven't been doing this for 12 years to stop right here. There's only so far you can take it in New Zealand and once you reach critical mass you either tread water or you diversify and take up directing or whatnot.
"If it wasn't for offshore productions then it would be very difficult for me to make a living. The bottom line is I'm going to go where the work is."
Map: The Battle of Helm's Deep
Herald feature:
Lord of the Rings
A long expected party
Best Lord of the Rings websites
