New South Wales U set. The U sets were a class of electric multiple unit (EMU) operated by the New South Wales Government Railways and its successors between September 1958 and November 1996. They were colloquially nicknamed U-boats.

Development
The New South Wales Government Railways began planning the electrification of the Main Western line over the Blue Mountains from 1949, and with that plan in full swing by the early 1950s, called tenders for 80 cars (40 motor, 20 trailer and 20 first with buffet trailer), with the contract was awarded to Commonwealth Engineering, Granville, in 1954. Electric traction equipment was supplied by the Metropolitan-Vickers, Manchester. However, before construction began the order was amended with the 20 planned first with buffet cars built as full first class seating cars, after a review of the New South Wales Government Railways conducted by American firm Ebasco Services Incorporated in the mid-1950s recommended the change.

The U sets were a bit different compared to the suburban single decked trains that were delivered at the same time. They were the first EMUs in NSW to feature stainless-steel construction using technology from the Budd Company, improving train acceleration and giving the trains lower maintenance costs and a longer usable life.

Delivery
The U Sets started to be delivered from June 1957, and the first sets made their first public appearances that same year. The first appearance took place on 22 June 1957 when they were hauled by electric locomotive 4625 as part of the first official electric train to travel on the newly electrified Blue Mountains line. Normal services began on 15 September 1958, and all were in service by March 1960.

The cars were numbered as:
Second-class motor cars: CF 5001-40
Second-class trailer cars: TF 6001-20
First-class (non-smoking) trailer cars: ETB 6021-40

First class travel was abolished on 1 September 1974. This saw the removal of the word "Second" on all carriages and also allowed non-first class passengers to enjoy the benefits of non-smoking carriages for the first time.

In service
The U sets initially entered revenue service on 15 September 1958 this being a Sydney Terminal to Mount Victoria service which was then known as "The Fish". The U sets initially operated on the Main Western line as far as Bowenfels which was the limit of the electrified system at the time. This was cut back to Lithgow in 1974. As the electrified network expanded they began to operate to Gosford (23 January 1960), Wyong (April 1982), Newcastle (June 1984), Port Kembla (February 1986) and Dapto (January 1993). The U sets were supplemented by V set double deck sets from 1970.

From the mid-1970s many had their original lift-up windows replaced by Beclawat sliding windows.

Withdrawal and preservation
Withdrawals due to accident damage include: 

 11/1/1973: CF5034 and ETB6033 burnt while stabled at Gosford, scrapped in March 1976
 3/1978: CF5038 and TF6018 damaged in a shunting incident at Flemington car sheds, scrapped in August 1981
 11/1/1982: CF5016 damaged at Gosford, cut up on site
 27/10/1983: CF5002 damaged in a shunting incident at Flemington, scrapped at Chullora
 25/12/1989: CF5009 damaged in a shunting mishap at Flemington Maintenance Facility and cut up on site during May 1990
 22/7/1993: CF5032 collided with electric locomotives 8627 and 8612 at Lithgow and cut up at Lithgow Maintenance Facility

Withdrawal of the sets began in 1994 as new Tangara G sets began replacing them. The first Tangara G sets entered service in June 1994 and as they were progressively put into service through to late 1995 the U sets were progressively withdrawn. The final run of the U sets on the Main Western Line for Blue Mountains services was in late February 1996 after which they only performed revenue services on the Northern Line between Sydney and Newcastle. The very last U Sets were withdrawn in early November 1996. The final revenue service performed by a U set was on Friday afternoon 1 November 1996 – a four car set operating a Newcastle to Sydney service.
The cars on the final passenger service were
CF5008 TF6004 TF6020 CF5022 on set U3. 

The final U set to run under its own power was a Sydney Electric Train Society Farewell tour two days later on the Sunday 3 November 1996 performed by an eight car set.

Like Minds (2005) featured car TF6011 in numerous scenes.

A number of U Set carriages have been preserved.:. Most of the cars allocated to the Hunter Valley Railway Trust were scrapped in 2013, excepting CF 5001. Richmond Vale Railway lost cars TF 6001/02 and ETB 6026 in a bushfire in 2017.

A preserved U set appeared in Guy Sebastian's "Standing with You" music video in 2020.
The NSW State-Owned Heritage Collection, managed by Transport Heritage NSW, has five U set carriages (CF5015, CF5017, CF5035, TF6013 & ETB6029) preserved and in custody of Historic Electric Traction who are currently restoring heritage U set "U2" to operational condition at Redfern.
Sydney Electric Train Society has CF5003 & CF5021 (stored at Lithgow) and CF5001, CF5022, TF6010 & ETB6037 (stored on a private property).
Valley Heights Rail Museum has ETB6039 on static display.
Dorrigo Steam Railway & Museum has CF5004 & CF5024 on static display.
Richmond Vale Railway Museum has TF6008, TF6009, TF6011, TF6012 & TF6019 stored.
Except the cars mentioned previously, all remaining cars have been preserved for private use.

References

External links
SETS article on the U sets

Electric multiple units of New South Wales
Train-related introductions in 1958
1500 V DC multiple units of Australia