503 EM 385-1-1 Sections 20-26

22.Q Turbine Maintenance Platforms (TMPs).

These TMPs are assembled in the draft tube below the turbine where they are physically attached to the structure. Some TMPs must be assembled below the turbine at the draft tube door level and raised into position and may also be required to be close to the turbine blades such that the TMP must wrap around the turbine hub. This applies to vertical access turbines where the TMP is assembled under the runner.

Note: This Section does not apply to standard off-the-shelf applications of scaffolds designed and used in accordance with ANSI A.10.

22.Q.01 Design.

1. TMPs must be designed and/or certified by a RPE. Existing TMPs must be certified prior to the next use. There is a grace period of 6 months from the effective date of this manual.
2. TMPs must be designed to support their own weight plus 4 times the maximum intended load.
3. A data plate will be attached or the documentation showing the design will be readily available on-site. The RPE will be listed on the drawings and calculations for the platform and not on the data plate. Data, when used, will include the following:
• (1) Descriptive name indicating intended usage;
• (2) Assembled weight of TMP;
• (3) Total maximum live load, pounds;
• (4) Total maximum distributed live load (psf);
• (5) Date of fabrication;
• (6) Name of fabricator;
• (7) Any load restrictions or usage limitations.
4. If wire rope is used to either support the platform after installation or to raise the platform while occupied, the wire rope must have a safety factor of 6.
5. Deflections in structural members and structural systems under appropriate service load combinations must not impair the serviceability of the structure.
6. If hooks are used to support the platform in its final position, they will be designed with a positive means of securing them to prevent the hooks from being disengaged.
7. The decking/platform must be designed so that the space between adjacent obstacles or structures and the space between the platform is no more than 9.5 in (24.1 cm) wide, except where the user can demonstrate that a wider space is necessary. Where gaps exceed 9.5 in, needed FP measures must be evaluated in accordance with Section 21.
8. The working surfaces must be slip-resistant.

22.Q.05 Testing.

22.Q.06 Assembly/Disassembly.

1. An AHA must be developed for the process of installing and removing TMPs. Fall protection, working over water, and fire protection will be addressed in the AHA along with any other hazards the workers identify. The AHA will be reviewed immediately prior to the start of work with the entire crew.
2. The TMP will be positively attached prior to use. Platform components must be supported and secured such that each component is stable in all anticipated load conditions. When attachment points are welded they will be either welded by an AWS certified welder or a pull test will be done in accordance with the RPE specifications.
3. Raising and lowering the platform, when occupied by personnel, will only be done with rated grip hoists or other lifting equipment rated for lifting personnel. Chain falls will not be used to lift personnel unless an independent FP system is used.

22.Q.07 Visual inspections must be done daily in accordance with Section 22.B.03.

22.Q.08 Training.

1. Employees that install and/or remove TMPs must be trained on how to properly assemble, install and the removal of the specific type of TMP. > See Section 22.B.06.
2. FP training must be done IAW Section 21.

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