Mercer railway station in Mercer, New Zealand, is 72 km from Auckland and 609 km from Wellington on the North Island Main Trunk line. It opened on 20 May 1875 and was closed to passengers about 1970 and to goods in the 1990s. It burnt down in 1879 and also in 1900. Until 1958 it was the first refreshment stop south of Auckland.

The line was extended to Mercer on 20 May 1875, though the pioneer British contractors, John Brogden & Sons, ran an excursion train the day before. The New Zealand Herald said, "This will be a busy station for some time to come, it being the terminus." It described the route as crossing Mangatawhiri swamp, then running beside the South Road, with a short branch line being constructed to connect with the Waikato Steam Navigation Company's boats. It said the station and other buildings were still being built. 'Some time to come' ended just over 2 years later, when the line was extended to Ngāruawāhia on 13 August 1877. The refreshment room was built in 1876/77 for £245 and extended in 1878/79 for £180.

The service began with two trains per day each way between Auckland and Mercer taking 2hrs 50mins. The station was unfinished when the railway opened.

An 1880 advert for reopening of the refreshment rooms said trains waited 20 minutes.

In 1902 the newly rebuilt station was described as, "a long wood and iron building, which contains a large refreshment room and bar, ladies' room, public room, booking office, stationmaster's room, and post and telegraph department. There is also a large engine shed, besides a pump house and coal shed, and there are eight cottages in the immediate vicinity", with 9 staff – stationmaster, porter, cadet, 2 engine drivers, 2 firemen, and 2 greasers.

Until New Zealand Railways took over in 1917, the "refreshment rooms" were managed by the Mercer Railway Hotel, opposite the station. The hotel was rebuilt in 1898, with 15 bedrooms, 3 sitting rooms and a 50-seat dining room. The refreshment rooms gained importance when dining cars on main trunk expresses were removed as a wartime measure.

The refreshment rooms became the target of poet A.R.D Fairburn's witty tongue with this very famous quip.

"The thought occurs to those who are entrained: The squalid tea of Mercer is not strained."

Traffic grew to a peak in World War 2, as shown in the graph and table below.

year	tickets	season tickets	staff	ref.
1881	1,763		3
1882	4,824		1
1883	4,330		3
1884	5,726		4
1885	5,536	2	5
1886	4,614	5	4
1887	4,675	1	2
1888	7,045	5	2
1889	8,127	3	3
1890
1891	7,686	3	3
1892	7,969	3	3
1893	7,519	5	3
1894	7,869	5	4
1895	7,951	7	4
1896	7,953	4	4
1897	8,652	4	5
1898	8,446	6	5
1899	9,605	3	5
1900	10,482	3	5
1901
1902	15,449		6
1903	16,365	1	8
1904	15,183	1	9
1905	14,912	14	9
1906	12,529	21	11
1907	11,619	29	10
1908	14,898	4	12
1909	13,977	8	12
1910	12,768	9	12
1911	11,055	20	11
1912	11,295	13	17
1913	14,199	52	17
1914	15,337	156
1915	15,898	144
1916	18,400	135
1917	20,601	113
1918	20,560	154
1919	20,680	111
1920	19,363	142
1921	21,203	125
1922	16,450	106
1923	14,535	101
1924	15,700	102
1925	17,615	107
1926	14,711	107
1927	14,696	68
1928	11,536	84
1929	10,218	133
1930	9,110	133
1931	11,892	94
1932	11,587	95
1933	14,141	99
1934	16,227	131
1935	18,030	127
1936	18,030	124
1937	19,560	111
1938	19,365	138
1939	19,802	175
1940	19,718	114
1941	19,667	128
1942	22,580	89
1943	25,422	92
1944	30,297	166
1945	31,073	145
1946	25,651	119
1947	21,410	185
1948	15,495	478
1949	14,838	337
1950	16,452	240

An engine cleaner died in 1899 after trying to jump onto a moving engine.

A Wellington to Auckland "Limited" express derailed on 28 October 1940 killing the driver and fireman and injuring 12 passengers. An estimate put the speed at 75 mph (though some at the inquiry gave evidence of normal speed) on the 30 mph (48 km/h) 8-chain radius curve, just south of the station, near the former 30.5 m (100 ft) tunnel opened out in 1937. The engine, K900, tipped on its side and was overrun by six carriages. Removal of the tunnel allowed double tracking and easing of the speed limit to 45 mph (72 km/h). The curve has been greatly eased in the 2006 Mercer to Long Swamp Expressway 4-laning of 12 km of SH1, which included this 1 km of rail deviation.

Another derailment at Mercer was on 3 September 2013, when a freight train blocked both the road and railway.

In 2011 a feasibility report on reinstating passenger services said a station with a platform 155m long and 750mm high for 6-car trains would cost $4m. The proposal was shelved. It is believed by some that the figure is overly inflated to kill off the proposal. Today, the Te Huia Hamilton - Papakura services passes Mercer but does not stop.

Heritage operator Mainline Steam Heritage Trust is developing a new depot at Mercer. By June 2020 three of their locomotives were stored in a siding at Mercer.

Photos

• view from above tunnel
• 1900s view from above tunnel
• about 1900 J Class locomotive and tunnel
• stationmaster on a jigger about 1902
• 1907 flood (New Zealand Graphic NZG-19070126-10c-1)
• 1936 photos of old tunnel, tunnel removal and construction tramway
• 1950s
• 1952 photo of track doubling work
• 1968 aerial
• from north and from south 1972 aerial
• aerial view of 4-laned SH1 and realigned railway

Map

• large scale map showing station, tunnel, wharf branch and 1940 crash site

Timetables

• 1876, 1877, 1879, 1880, Feb 1882, Mar 1882, Sep 1882, Jan 1883, Mar 1883
• Appeal by porter against military service in 1918

Preceding station	Historical railways			Following station
Pokeno Line open, station closed		North Island Main Trunk New Zealand Railways Department		Amokura Line open, station closed