dna special: Host of technical issues dog monorail

The Mumbai Monorail recently suffered a recurrence of a problem with the constant velocity joint that is giving the operators a nightmare. What's also a worry is that Scomi, the rake manufacturer, has been procuring spare parts locally instead of sourcing them from its plant in Malaysia.

"On August 16, when the rolling stock number 9 (blue colour) was coming from Chembur to the Wadala depot at around 3.30pm, a security guard at VNP-RC Marg monorail station heard an unusual sound emanating from the train and alerted the train pilot," said a source.

The problem was noticed in the intermediate rake – car number 3. The nuts-bolts that hold the constant velocity joint had broken and the part was lying on the plate just below. But no fault message was flashed on the dashboard of the pilot's cabin.

The pilot informed the operations control centre, who instructed that the service continue to operate with passengers at a speed less than 10kmph. When it reached Wadala depot, the rake was taken for repairs.

The previous two instances with regard to the constant velocity joint occurred on June 11 on rolling stock 8, and earlier in April-May when trials were underway. The recurrence of the problem has raised serious concern with regard to the quality of the machinery manufactured by Scomi.

UPS Madan, commissioner, Mumbai Metropolitan Region Development Authority, confirmed the problem saying, "There are some issues with the constant velocity joints and this is being looked into."

Asked whether there was a risk in not getting passengers to disembark when the problem occurred, Madan said the decision to operate the rake at a slow speed was sufficient.

On the matter of procuring spare parts, he said, "Constant velocity joint comes from abroad. But as some of the trains are not being used for regular services, parts were taken from these rakes. There is no problem with buying some spares like bolts and nuts from the local market."