The Kalka-Shimla mountain railway is one of the best-known railway lines in India and has featured in a number of literary works and at least one BBC documentary in recent years. This is intended to summarize the main points about the line as it is today. The route was opened as a whole (95.68 Km) on 9 Nov 1903. A further 0.77 Km to the “Old bullock train station” was opened on 27 Jun 1909. Possibly the present line (length 95.57 as per current railway database) includes a small portion of the extension. Here we have a list of stations (in both directions). This information is taken from the site http://rbs.indianrail.gov.in/ShortPath/ShortPath.jsp which is useful for the dedicated railfan. I have added the altitude data from passenger timetables. The distances shown below are actual distances, and I am not getting into the complexities of chargeable distance here.
The main technical point is that the ruling gradient is 1 in 33 uncompensated. Those who are really fond of number crunching can find the gradients between intermediate stations. Here are the summary of trains running in both directions in May 2015.
As you can see, trains are listed as having AC chair car, First Class and Second Class seating. The railcars have only first class. The Shivalik Express and the Himalayan Queen have non-AC seats which are somewhat better than the second class seats, but are charged using the fare tables for AC chair car. The three trains other than the railcar and Shivalik Express have unreserved second class seats, though reserved seats are available only on one train as you can see above.
It is common for the average person or media source to refer to the trains on this line as a toy train. This appears to be unjustified as the trains are as long and as heavy as their narrow gauge counterparts on the plains. And the volume of passenger traffic (at least 5 pairs of daily trains) would be more than that on many broad gauge and metre gauge branch lines.
Additional railcars and trains may run at short notice during the summer. These are generally not given in the printed timetables. However, most knowledgeable travellers have now shifted to the online timetables. The most user-friendly is probably http://erail.in/ from where the above tables are taken. One can also use this website to get timetables for individual trains, such as this one for the downward Himalayan Queen:
As you can see, this train stops at about half the stations. It seems to have a rake of 5 reserved coaches and two brake cum unreserved coaches. Barog appears to be a mandatory stop for all trains for catering purposes. In fact there is not much of a local population and this station seems to exist only for catering purposes. The station is named after a British construction engineer named Barog (though this does not sound like a typical British surname).
This train connects with a BG express train to New Delhi in both directions. That is also called the Himalayan Queen, though it starts from Kalka with a number of coaches which are removed at Panipat and proceed to Bhiwani as the Ekta Express. There are also two Shatabdi Expresses to New Delhi and the long-standing Kalka Mail to Old Delhi and Howrah, which is probably one of the oldest long-distance trains on IR. There is also a link train which connects Kalka to the Paschim Express to and from Mumbai.
There are many videos about this line available on Youtube; as a sample here are some taken by my family in 2010:
Shivalik Express: https://www.youtube.com/watch?v=wO0NifZGk9w
And from Shimla to Kalka by the Himalayan Queen, plus a bit of Chandigarh: