He says: "Spar is the market leader in convenience, but it is a whole new ballgame for Tesco. Fallout will come from small independents."
The 58-store Spar chain, which operates along the M62 corridor, is forging ahead with plans to increase its portfolio to 100 in the next five years, with three new-build stores due to open by Christmas.
Calderbank says: "It's location, location, location. You must walk the streets, see where people work, where the NCP car park is, and see which is the busiest side of the road. If nothing is there, we will try to create a site, but we walk away if the location is not right."
Alfred Jones is partnered with both Texaco and Shell at its five existing petrol retail sites and Calderbank is keen on further forecourt opportunities, happy to work with other oil companies to expand the estate.
"My aim is to build the best family-owned convenience chain in the UK", he says.
Chairman John Jones claims to have filled his first shelf at the age of eight. Family values are important to the business, and this helps to prevent high staff turnover which afflicts many other convenience operations.
At Alfred Jones almost 30% of the staff have been with the company more than five years, and 10% for 10 years or more. Calderbank himself has been with the company for 20 years.
Staff training also helps retention, keeps morale high and makes staff very aware of shoplifters.
Calderbank says: "The best form of security you can have is your staff. We do a lot of staff training, and we offer them the opportunity to take national vocational qualifications."
In spite of all its precautions, which include CCTV in every store, the chain falls victim to 20 armed robberies a year and it is particularly vulnerable at Christmas.
Retailing's harsher realities
But Calderbank refuses to let some of the harsher realities of convenience retailing get him down. He laughs when he recalls a recent ram raider who unknowingly locked himself inside one of the stores and set off the burglar alarm.
He was unable to escape from the premises and had no option but to wait until the police arrived accompanied by an Alsatian dog to ensure he didn't make a getaway. "Well, you have to look at the funny side," says Calderbank.
The Jones' first store opened in 1888, specialising in tea and bacon. It became one of the first cash and carry operations under the Vivo banner through the 1960s and then as Spar.
Calderbank says it has been able to plough its resources into becoming Spar's biggest independent operator, after divesting its wholesale operation to Preston-based James Hall in 1998.
Alfred Jones is now James Hall's biggest customer and Calderbank says: "We have a great partnership. The bottom line is that James Hall is the best independent wholesaler in the UK. We are now focused on retailing we were sidetracked by cash and carry before."
Alfred Jones' Warrington headquarters and adjoining Spar have been extended since the wholesale business was sold.
"Management now has a boardroom to meet in after years of gathering in the kitchen. But old habits die hard, and the board still gravitates to the kitchen for tea and meetings.
Meanwhile all stores are being upgraded and 70% of the estate is at stage one or above of Spar's Millennium store standard. All will have been revamped by June 2003.
Turnover is on the up too and in five years time is expected to reach £120m from today's £65m.
"Tesco Express's arrival won't be a problem for us competition is a good thing," Calderbank says.