In the meantime, Mr Tan, 33, who's director of the industrial rope access division , said that there were important lessons that could be learnt.
One was that the standard operating procedure (SOP) for an evacuation needed to be agreed upon by everyone.
For example, the response time for Dive-Marine to arrive on the scene had not been fixed in the SOP.
Dive-Marine Services director Sean Tan
When the Flyer stalled after an electrical fire at 4.50pm on 23 Dec, Dive-Marine Services were called by the Flyer management at 5.20pm to mobilise its team in case it needed to deliver food or medicine to passengers or to lower them down.
Caught in a traffic jam on the Ayer Rajah Expressway, Dive-Marine arrived at 7pm - less than two hours after they were alerted, which Mr Tan felt was acceptable.
The team eventually lowered 11 people in about four hours before the Flyer finally began moving again at about 11pm.
Another lesson was who should be called in if such an incident happened again.
Members of the public have written to the media slamming the Flyer for its poorly coordinated rescue plans and asked if rope access was the best method to do it.
A Flyer spokesman said it decided to use ropes while efforts were being made to restore the wheel movement.
Mr Tan said that for this episode, Dive-Marine were called in first because it knew the key access areas and the shortest way to reach the capsules.
But he felt the Singapore Civil Defence Force (SCDF) and the police should also be called in quickly to help in the evacuation and cordoning of the area respectively.
Said Mr Tan: 'We went there as the standby team. When we were told we had to evacuate 173 people, I explained to the Flyer it would take a long time given the manpower and equipment available and I requested the help of the SCDF.'
The SCDF was then called in.
New to S'pore more training is needed
When asked about the Flyer's protocol on whom to call, a spokesman replied in an e-mail: 'Our protocol is to always inform the authorities and our technical people and also at the same time, mobilise our rescue team members.'
Mr Tan said a chain of command was currently being worked out between the Flyer, Dive-Marine, the SCDF and the police.
He added: 'The rescue team from the London Eye came last Tuesday for a discussion and they said the rope access technique was similar to their rescue techniques.'
He added there was no known government agency to delegate who was responsible for such a rescue.
The SCDF, which conducts its own high-rise rescues when needed, said it was not responsible for the certification of companies to conduct high-rise rescues.
The Ministry of Manpower also said this issue did not come under its purview.
A police spokesman said they were not the licensing authority for rescue work.
Said Mr Tan: 'Such a thing is still new to Singapore.
'We have to train together with the SCDF to get the correct procedure and to be better co-ordinated. For example, ambulances need to know where to park.'
Another recommendation by the Dive-Marine team was to put in evacuation tools like auto descenders in each capsule.
These are ropes, making up a pulley system, where one person is lowered in a harness while another harness is concurrently being raised to the capsule.
He said it could have halved last month's rescue time.
The ropes are 300m long and need to be customised in the UK. The ropes they used in the rescue here were only 200m long.
Using the 300m long rope, they can lower the people from the highest capsule, which is 165m above the ground, to about three stories above the ground where there is a staircase to walk down from an access point.
Food supplies should also have been prepared by the time his team reached the Flyer, said Mr Tan. He said those supplies were not ready during last month's incident.
The London Eye stores equipment such as water, portable commodes and even blankets to keep stranded passengers warm.
And packages for people to relieve themselves should also be available in each capsule, said Mr Tan.
These were not present then and he said some people defecated on the capsule floor.
He said that from discussions with the London Eye officials, at which he was present, there were suggestions to provide blankets to cover passengers while they relieve themselves.
Packs that could absorb urine and its smell should also be provided.
He added: 'Given a choice, it would have been better not to lower people down because it was quite traumatising for them. This method is really the last resort.'
As to whether Dive-Marine was licensed to perform such rescues, and who was responsible for issuing such licences in the first place, Dive-Marine said its team is trained in rope rescue and follow guidelines set by the Industrial Rope Access Trade Association in the United Kingdom.
Top photo - A BETTER WAY:One recommendation by Dive-Marine Services is to put in evacuation tools like auto descenders in each capsule.
This article was first published in The New Paper on Jan 9, 2009.