I highly doubt that tram style street tracks will support the weight of vehicles carrying retention toilets with all the associated plumbing and weight of fluids. Not to mention the performance penalty compared with other trams.
And yet such tram-trains exist, and are manufactured by (atleast)
Alstom and
Stadler.
With modern crash standards, the weight of the toilet and it's tanks are not that large compared to the mass of the vehicle.
Like it or not the demand in this country is for through services although high quality connections can be acceptable. The connection between Wallgate and North Western stations is not such a thing. And extended journey times are unlikely to be welcomed either. What the Greater Manchester portion of the Kirkby line needs is a half-hourly through service to Manchester with the Atherton line providing the most useful local links. The proposed Skelmersdale scheme would allow just such a service.
The journey time from Wallgate into Manchester is 42 minutes.
It's about 27km to Victoria Station.
Victoria Station to Rochdale on the tram line is about 24km and takes ~48 minutes.
Worth noting that that is with a 50mph top speed, whereas with tram trains 60mph is available.
But either way, its not going to be a catastrophic change in journey time.
And whilst they lose direct trains and suffer marginal inconvenience from changing trains, they also gain a high intensity service to a far closer urban area.
Worth noting that from Kirkby, a significant fraction of the time nationalrail recommends doubling back through Moorfields!
Tell them they can have four trains an hour to Wigan and Liverpool, or the present situation with a slow 2tph service to Manchester and no through service to Liverpool... I'm honestly not sure what I would pick.
For which there is almost no demand. Pure crayonista.
Given that Kirkby alone has far more passengers than all the toher stations on the Manchester portion of the line combined, this is almost certainly not true.
Why would you take an hourly DMU to Kirkby and change when you can just drive to a Merseyrail station of your choice?
Rainford is ~35k users.
Upholland is ~35k users
Orrel is ~95k users
Pemberton is ~70k users.
So in total something like ~235k users.
Kirkby has ~2.5 million.
Where do you propose this huge number of passengers comes from?
Hell, it even beats it if you all count all of Wallgate's passengers!
Kirkby is only 16 minutes from Moorfields and thus Central Liverpool.
That puts Upholland 30 minutes from central Liverpool, even using sectional timings from the current timetable for the branch line section.
Even from Wigan Wallgate itself you would be looking at about a 41 minute journey time to Liverpool.
Upholland is 30 minutes to Liverpool or 54 minutes from Manchester - and can pick up traffic from the like of Skelmersdale as it would then be the closest merseyrail station.
Can you really say that the people of Skelmersdale would prefer two trains an hour to Manchester that take 54 minutes to four trains per hour to Liverpool that take 30?
Once again I'll say that tram-train on the Atherton line could be useful but as a supplement to the current range of services, not a replacement.
But it is likely that having a "mix of services" will cause serious operational problems and reduce the number of trains that can be operated - since you will apparently want a mix of stopping patterns, which causes all sorts of problems.
The traffic potential of the main part of the Atherton line is likely to be drastically greater than this small Kirkby branch line.
There are three practical options if tram trains are to be introduced on the Kirkby Branch line.
1. Split the service at Wigan and hopefully extend Merseyrail to meet it at Wallgate.
2. Try to operate trains on the Kirkby Branch line via either Bolton or Chat Moss
3. Extend the tram train to Kirkby. This preserves the apparently essential through services but avoids any operational nightmares caused by trying to mix and match on the Atherton line.
The binliner traffic flow is all Merseyside's rubbish. You cannot just cut it by half! If half the flow were transferred to road, that would be 40-odd containers being individually hauled across the Pennines and back daily.
So not much at all?
40 lorry round trips a day is nothing.
Have you seen the M62?
In order for two sets of empties to return to Knowsley in the small hours, avoiding the Atherton line, three interworked diagrams would be needed, with some long layovers. During the night all three trains would be on the move concurrently, each with a loco and driver, so there would be a substantial increase in operating costs compared with the current two trains.
Well if they can't make it work then at least half the traffic would just go over to the road.
40 lorry journeys over the pennines is nothing compared to the transport potential for a properly utilised Atherton line.