South African Class GL 4-8-2+2-8-4 a pair of Class 14 4-8-2 steam locomotives. The success of the Class GA Garratt in proving the suitability of the Garratt design for South African conditions coupled with the economies in crew, fuel and water consumption it offered, provided an incentive for the SAR to consider a new Garratt class for use on the Natal mainline. The aim was to eliminate double-heading as a regular practice with such a locomotive to be equivalent to three of the Class 1E electric locomotives which were then in use, or two Class 14 steam locomotives. Colonel F.R. Collins DSO, the Chief Mechanical
1/2 + 1/4 + 1/8 + 1/16 + ⋯ 1/2 + 1/4 + 1/8 + 1/16 + ⋯ In mathematics, the infinite series is an elementary example of a geometric series that converges absolutely. There are many different expressions that can be shown to be equivalent to the problem, such as the form: 2 + 2 + 2 + ... The sum of this series can be denoted in summation notation as: As with any infinite series, the infinite sum is defined to mean the limit of the sum of the first terms as approaches infinity. Multiplying by 2 reveals a useful relationship: Subtracting from both sides, As approaches