The boss of Ferguson Marine has said it is making “progress” with the two vessels due to service CalMac routes on the west coast.
After eight years of construction, David Tydeman said “mistakes” had been made, but the ferries would be delivered to the new timescales.
Yesterday the wheelhouse of Hull 802 was lifted into place.
The boats, the Glen Sannox and Hull 802, are eight years late and millions over budget.
In an interview for BBC Scotland’s Good Morning Scotland, Mr Tydeman said: “I think the build strategy adopted in 2015, when we all look back in hindsight, was unwise, it embedded costs.
“It was partly because the design wasn’t finalised and I gather there were a lot of conversations going on between CMal and FMEL [Ferguson Marine Engineering Limited] about finalising the design.
‘Easy to look back and be critical’ about Ferguson Marine’s ferry plan
“It’s easy to look back and be critical, but the decision to build an empty ship and put things in later is unconventional and has added cost.”
CMal is the owner of Scotland’s ferry fleet.
The ferries will be the newest on ferry operator CalMac’s ageing fleet.
“All the brackets, all the racks that hold things could have been done while this was upside down in the shed as a module. Instead this had to be done on ladders, on scaffolding, working in the ceiling.
“It doesn’t matter if you’re building a kitchen, building a skyscraper or building a ship. It’s the same basic things. Is the design complete? Have you got the specification? Have you got the right plan to do it in the right sequence?”
He continued: “One of the problems with a car ferry is that you have to squeeze all your systems below and around the car deck. So you pack in your engineering, your systems, your pipework into confined spaces and that makes it complicated.”
The Glen Sannox is scheduled to be handed over to CMal by the end of this year. It will then be deployed on CalMac’s Arran route.
‘I think she’ll be a pleasant surprise’
He continued: “I think she’s going to be a great ship. There’s good capacity for car carrying and lorries. I think she’ll be a pleasant surprise.
Last month, Wellbeing Economy, Fair Work and Energy Secretary Neil Gray told MSPs it would be cheaper to scrap the ship and place a new order with an overseas shipyard.
Mr Tydeman said: “If ministers or CMal decided to order a ship from Turkey, you’d have to wait many years to get another ship. This is going to be a good ship, and I think it was the right decision.
“We’ve been very careful on [Hull} 802 to plan the learning from this ship – capture it, clean up the design drawings, make sure that before we start putting things inside 802 we’ve captured all the learning from 801.”
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