The 2015 Concrete Placing Boom-Manual Spider in Greenland refers to a specific type of equipment used in the construction industry. A concrete placing boom is a mechanical arm that is used to accurately place and distribute concrete in construction projects. The "manual spider" likely refers to a type of placing boom that is manually operated. Greenland, in this context, likely refers to the location where this particular concrete placing boom was used or demonstrated. This could have been part of a construction project, a demonstration, or a training session. Overall, the title indicates a specific instance or event related to the use of a concrete placing boom in Greenland in the year 2015.