Many private companies operated horse trams in Adelaide from 1878 until 1917 on routes that eventually ran for more than 100 kilometres within a radius of the Adelaide General Post Office, as shown in the map in the infobox. The trams were extremely popular, since they were more comfortable than the horse-drawn jaunting cars, carriages and omnibuses that operated on the poorly formed roads of the time. The majority of people in the Adelaide suburban area, as it was then, were within walking distance of a horse tram route.

The companies laid tracks and ran trams wherever demand was apparent, and most remained in business for up to three decades. However, Adelaide was eventually the last capital city in Australia to be without faster, higher-capacity, cleaner electric or cable trams; the public eventually saw the quaint vehicles as a blot on their city's image and clamoured for electric trams. However, in the early years of the 20th century, following a sustained large-scale drought and with increasing popularity of the "safety bicycle", few of the companies were making a profit and none could afford the capital cost involved.

In 1907 the South Australian Government bought the companies' assets and formed the Municipal Tramways Trust (MTT) to establish electric tram services, which were opened from 1909. Electrification generally proceeded rapidly. However, for the next eight years horse trams provided interim services, under MTT ownership, while electric transmission infrastructure and new tracks were progressively completed. Horse trams ceased running on Adelaide-centric routes in 1914 and on the isolated Port Adelaide lines in 1917, 39 years after the first horse trams operated.

Investigations Public transport was beyond the financial reach of many people in Adelaide's early days following European settlement in 1836. However, the 1870s brought good harvests and prosperity to South Australia, and one of the consequences was a vast improvement in Adelaide transport services through the widespread introduction of horse buses, which charged fares about one-fifth those of coaches. But despite some good services, many of the operators had little regard for their customers' interests: complaints were made that the conveyances were filthy, with faded and ragged seat cushions and compartments rarely swept out.

During the early 1870s Sir Edwin Smith and Mr W. C. Buik, both prominent in Kensington and Norwood Corporation then Adelaide City Council (and both later mayors of Adelaide), spent some time inspecting European tramways. They were impressed with horse trams, since one horse hauling a tram could move three to ten times as many people compared with a horse-drawn omnibus and the ride was far superior. On returning to Adelaide they promoted the concept. In April 1875 they issued a prospectus for a new joint stock company, the Adelaide and Suburban Tramway Company. Private commercial interests lobbied the state government for legislative support, over Adelaide City Council's objections related to licensing and control.

Public expectations were favourable, reflected by an editorial comment in The Register newspaper:Of the advantage of street tramways there can be no doubt. Whatever incredulity might at one time have existed upon the subject is now entirely removed by the great success which has attended their introduction in England and on the Continent of Europe, as well as in America. ... There can be no question that Adelaide is greatly behind many modern cities in facilities for street conveyance, those which are provided being in many respects a long way behind the times. The experience of other cities where railways worked by horse traction have been in use for some time is universal in their favour. The unpleasant jolting which is a general characteristic of a ride in most of our city conveyances is done away with, and greater safety and convenience are ensured.

The Adelaide and Suburban Tramway Company had prudently refrained from committing itself to ordering equipment until the Parliament of South Australia passed the necessary private Act granting powers to construct and operate the line. It was 19 months before that occurred, especially since considerable opposition was raised by the Corporation of the City of Adelaide, mainly over who should have the right to control and license the cars.

The first horse tram line

Construction of the tram lines, eventually totalling 119 km (74 mi), was entirely by manual labour supplemented for some tasks by horses.

In addition to rails and sleepers, the Adelaide and Suburban Tramway Company ordered twelve new cars – eight single-decked 18-seaters and four double-decked, with 22 seats downstairs and 24 upstairs – from the John Stephenson Company of New York in the United States.John Stephenson, an American coachbuilder, invented and patented the first streetcar to run on rails in the United States. Another 12 months therefore elapsed before the Governor of South Australia ceremoniously laid the first rail on 29 October 1877.

The company began its first service from Adelaide to Kensington Park without further ceremony on 10 June 1878.

The service became the first permanent tramway system of an Australian city.The word "permanent" is the operative word in the Adelaide "first tramway" claim: the first tramway to operate in Australia ran along Pitt Street in Sydney in 1861 but closed in 1866. Ironically, in due course Adelaide would become the last Australian capital city to discard horse trams for more modern public transport – but in 1878 horse trams everywhere were a source of wonder, reflected in Henry James's novel The Europeans, published in that year:From time to time a strange vehicle drew near to the place where they stood – such a vehicle as the lady at the window, in spite of a considerable acquaintance with human inventions, had never seen before: a huge, low omnibus, painted in brilliant colors, and decorated apparently with jangling bells, attached to a species of groove in the pavement, through which it was dragged, with a great deal of rumbling, bouncing and scratching, by a couple of remarkably small horses. When it reached a certain point the people, [mainly] women, carrying satchels and parcels, projected themselves upon it in a compact body – a movement suggesting the scramble for places in a life-boat at sea – and were engulfed in its large interior. Then the life-boat ... went bumping and jingling away upon its invisible wheels, with the helmsman (the man at the wheel) guiding its course incongruously from the prow.

A writer in The SA Register in September 1877 rhapsodised about the American tram cars then being assembled by Adelaide company Duncan & Fraser:The object sought to be attained in all American vehicles and machines is a maximum of strength with a minimum of weight, and the manner in which this has been effected in the tramway cars is both interesting and wonderful. ... Though rather different in form to anything we have previously seen in this city the car is very elegant in appearance, and is painted and ornamented in the most chaste and tasteful manner. ... The interior of the car is elegant in the extreme. It is fitted throughout in native American woods, all of light colours and varnished. The seats which run along the sides are marvels of lightness, cleanliness, and comfort. ... The ventilation – that most important consideration in a climate such as ours – is thoroughly provided for by means of adjustable panels in the ceiling.

The Kensington service was so successful that on 9 December 1878 the Adelaide and Suburban Tramway Company was able to open its North Adelaide line, satisfying a key proviso of the Act that it was to construct 10.8 miles (17.4 km) of track from Adelaide's city centre to the suburbs of Kensington and North Adelaide within two years; the goal for Kensington had been reached in May 1878. By 1907 the company owned 90 trams and 650 horses, and had its own tram factory at Kensington.

Growth of the network The network continued to be developed solely by private companies. The routes were laid to meet market demand and when services were introduced they were extremely popular. Eleven companies built lines between 1878 and 1883.The companies were as follows: Three companies had failed before laying tracks; evidence suggests they were floated to encourage land speculation, as well as being a speculative investment themselves.

The South Australian Parliament subsequently passed legislation authorising other companies to build new lines. Some of the Acts provided for "steam or other power" in addition to horses.In this period the world's first operational electric tram service opened in Berlin (1881).

Within six years of the first line being authorised, companies were operating the following lines:

Another isolated route was opened from Glenelg to Brighton in 1883. Earlier (in 1879) a steam-hauled broad-gauge line had been opened from Marino, five miles to the south of Glenelg, passing through Brighton and terminating at Jetty Road, Glenelg. The line ran for most of its distance on the edge of scrubby sand hills fronting the beach. It closed after 15 months. In September 1883 two horse tram routes were built: one along the Brighton Road from Glenelg to Brighton, which lasted until February 1914, and another in the southern streets of Glenelg, which closed after 18 months. The South Australian Government did not purchase the assets of the Brighton company nor the Port Adelaide company.

The Corporation of the City of Adelaide took responsibility for controlling the disparate services. By-laws imposed a speed limit of 8 mph (13 km/h).

By 1901 the horse tram companies had 74 miles (119 km) of tramlines, 162 cars and 1062 horses.

Infrastructure

In accordance with the horse tramway companies' enabling Acts, all lines were built to a gauge of 4 ft  ins (1435 mm standard gauge, except for the Port Adelaide to Albert Park line, which was built to 5 ft 3 ins (1600 mm) broad gauge to accommodate steam locomotives, all of which in the Adelaide area were to that gauge. (This line was also notable for having embankments to avoid swampy ground and flooding.)

Most streets at the time were unsealed, although some heavily trafficked roads were built with the macadam process. Regardless, the surfaces were made soft between the rails to aid the horses' traction. The condition of the streets – muddy in winter and dusty in summer – also militated against the introduction of street-level steam trains, which had started operating five years earlier: precursors to what became the Glenelg tram line service.

Various streets needed to be widened especially for tram lines, including Brougham Place, North Adelaide by and Prospect Road to a total width of .

The route map in the infobox shows the horse tram network in the 1900s, when they were at their maximum extent. City-centred routes had termini at Henley Beach, Hindmarsh, Prospect, Nailsworth, Walkerville, Paradise, Magill, Burnside, Glen Osmond, Mitcham, Hyde Park and Clarence Park. Port Adelaide–Albert Park and Glenelg–Brighton were isolated lines.

Horse trams ran at an average speed of about , usually two horses pulling each tram from a pool of four to ten. However, the largest trams were hauled by three horses, especially when going up and down hills. Most of the companies operated double-deck trams with an enclosed saloon at the bottom and an open top deck, although some were single-decked. Many were built by the John Stephenson Company of New York, Duncan & Fraser of Adelaide, and from 1897 the largest of the companies, the Adelaide & Suburban Tramway Company, built its own at Kensington.

Life on the horse trams