See News: http://www.railpage.com.au/news/s/tired-old-sydney-train-station-to-become-worldclass-precinct

If the Wynyard redevelopment actually goes ahead, a couple of thoughts:

1. Move Kings Carpark to some place west of Blacktown (i.e don't encourage cars into the city) and at least ensure that the Wynyard 1 and 2 platforms can be re-activated at a future time less addicted to roads, such that the lines intended for the eastern side of the Harbour Bridge _could_ be re-invented,

2. If developers want to build more office space in the CBD, perhaps they should contribute to putting in the extra stations and second city loop originally envisaged?

My unexpert opinion is the following should be required:
1) The platforms are rebuilt as 250m long perfectly straight platforms. The width of platforms needs to be increased as well. This should be the minimum standard for all new (and rebuilt) platforms.
2) As normw said, all 6 platforms are built allowing for the rails to be reinstated on the harbour bridge. (And provision for tunnels in other direction towards Town Hall.)

My unexpert opinion is the following should be required:
1) The platforms are rebuilt as 250m long perfectly straight platforms. The width of platforms needs to be increased as well. This should be the minimum standard for all new (and rebuilt) platforms.
2) As normw said, all 6 platforms are built allowing for the rails to be reinstated on the harbour bridge. (And provision for tunnels in other direction towards Town Hall.)

Not quite what I said or meant. The current width of 3/4 and 5/6 platforms is largely fixed by the tunnel spacings feeding them, and the same width and limitation would apply to 1/2 if re-activated, unless MAJOR reconstruction is carried out. The southern end tunnels of 1/2 platforms terminated in short dead-ends, but based on a 1926 proposal, were envisaged to continue. A junction north of Town Hall 4&5 today could potentially give Illawarra trains access to North Sydney/North Shore if the Harbour Bridge east side tracks were re-implemented. Platforms 5/6 at Wynyard go via Circular Quay/City Loop and not the Bridge.
Edited; See 'Fred Scuttle' below.

The need for wide platforms is largely dependant on passenger wait time between trains during peak hours; if 1/2 were re-activated for North Sydney/North Shore services, the effective platform width for thoses services would be doubled; passengers could also board Illawarra/South Coast services in addition to first going to Town Hall.

Actually, Platforms 4&5 at Town Hall were planned from the start to be part of the Eastern Suburbs Line. When the City Railway was being constructed in the early 1920's, the planned route for the Eastern Suburbs Line was to run from underground platforms at Railway Square (from the Inner West) to Town Hall 4&5, and then to underground stations at Pitt & Market Streets (the present-day Pitt Street Mall), O'Connell Street, St James (unused platforms 2&3), Liverpool & College Streets (the present-day Whitlam Square) and then on to Bondi Junction via Taylor Square and Paddington. After the Central-St James and Central-Wynyard-North Sydney sections were opened in 1926 and 1932 respectively, construction of the ESR had not progressed beyond construction of the platforms at Town Hall and St James, as well as stub tunnels at each end of these platforms (those at St James being utilised for turnback facilities). When construction resumed in 1947 (which would stop in 1952, and not start again until 1967), it followed a new route, which bypassed St James, and eliminated the other proposed stations, running via Martin Place and King's Cross.

The intended route of the line south of Platforms 1&2 at Wynyard would have been to Pitt & Market Streets (at a lower level, and at an angle to, the Eastern Suburbs platform), then to a station beneath the intersection of Wentworth Avenue and Goulburn Street, and then to an underground platform at Central (beneath Chalmers Street).

I should have added that there is a map of the underground lines as proposed in John Oake's book, Sydney's Forgotten City Railways, on pages 14-16.

Actually, Platforms 4&5 at Town Hall were planned from the start to be part of the Eastern Suburbs Line. When the City Railway was being constructed in the early 1920's, the planned route for the Eastern Suburbs Line was to run from underground platforms at Railway Square (from the Inner West) to Town Hall 4&5, and then to underground stations at Pitt & Market Streets (the present-day Pitt Street Mall), O'Connell Street, St James (unused platforms 2&3), Liverpool & College Streets (the present-day Whitlam Square) and then on to Bondi Junction via Taylor Square and Paddington. After the Central-St James and Central-Wynyard-North Sydney sections were opened in 1926 and 1932 respectively, construction of the ESR had not progressed beyond construction of the platforms at Town Hall and St James, as well as stub tunnels at each end of these platforms (those at St James being utilised for turnback facilities). When construction resumed in 1947 (which would stop in 1952, and not start again until 1967), it followed a new route, which bypassed St James, and eliminated the other proposed stations, running via Martin Place and King's Cross.

The intended route of the line south of Platforms 1&2 at Wynyard would have been to Pitt & Market Streets (at a lower level, and at an angle to, the Eastern Suburbs platform), then to a station beneath the intersection of Wentworth Avenue and Goulburn Street, and then to an underground platform at Central (beneath Chalmers Street).

Thanks for pointing out my error regarding the proposed route for Wynyard 1/2, and have edited my previous post to correct the mis-information on my part.

The Wynyard 1/2 stub tunnels were the only part (AFAIK) of that proposed route to be built (not counting the 'un-used' 26/27 platforms at Central); I only suggested joining them to Town Hall 4/5 as one possible use, to 'justify' retention of Wynyard 1/2 platforms for some future use. In recent years there have been a number of proposals to remove the Cahill Expressway over Circular Quay, often for no other reason than visual aesthetics. If that closure ever did happen, there would be a relatively simple path back to the northern east-side approach to the Harbour Bridge. AFAIR the bridge that jumped Milsons Point 1/2 to North Sydney yard was scrapped.

Thanks for pointing out my error regarding the proposed route for Wynyard 1/2, and have edited my previous post to correct the mis-information on my part.

The Wynyard 1/2 stub tunnels were the only part (AFAIK) of that proposed route to be built (not counting the 'un-used' 26/27 platforms at Central); I only suggested joining them to Town Hall 4/5 as one possible use, to 'justify' retention of Wynyard 1/2 platforms for some future use. In recent years there have been a number of proposals to remove the Cahill Expressway over Circular Quay, often for no other reason than visual aesthetics. If that closure ever did happen, there would be a relatively simple path back to the northern east-side approach to the Harbour Bridge. AFAIR the bridge that jumped Milsons Point 1/2 to North Sydney yard was scrapped.

They have been trying to close the Cahill for 30 years since the SHT was first proposed. Its still there and will be still there for many decades to come.

i suspect there is no future in the former tram lines over the bridge to ever see rail use again. A new greenfield tunnel is to be built for rail. To put rail over the bridge would mean 2 extra lanes of capacity would have to be built to replace, won't happen! Rail tunnels are far cheaper than road tunnels. Also once the railway is on the nth side of the bridge, then what? The original proposal was a line to the nth beaches, this won't happen. Any line to the nth beaches will be an extension of the Metro project in the future.

They have been trying to close the Cahill for 30 years since the SHT was first proposed. Its still there and will be still there for many decades to come.

i suspect there is no future in the former tram lines over the bridge to ever see rail use again. A new greenfield tunnel is to be built for rail. To put rail over the bridge would mean 2 extra lanes of capacity would have to be built to replace, won't happen! Rail tunnels are far cheaper than road tunnels. Also once the railway is on the nth side of the bridge, then what? The original proposal was a line to the nth beaches, this won't happen. Any line to the nth beaches will be an extension of the Metro project in the future.

I did say keeping Wynyard 1/2 safe for a less car-addicted time... The original lines to the northern beaches (and possibly the Warringah peninsula) were begun in the North Sydney train tunnels but (as usual) never continued. If Gov't would get passed making it essential for people to work in the CBD and implement polices that would allow people to work (where possible) from home, peak hour would largely vanish and a lot of people working in 'support' roles (food, retail, etc) would also have less pretext to come into the Sydney centre, and we probably COULD DO WITHOUT extra car lanes on the bridge.